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10Base-T - Twisted Pair Ethernet - a derivative of the Ethernet (IEEE 802.3) standard for Local Area Networks (LANs) using twisted-pair cable of up to 100 meters, operating at up to10 Mbps. The cable is thinner and more flexible than the coaxial cable used for the 10Base-2 or 10Base-5 standards, and connects with RJ-45 connectors. Typical application are star configurations of up to twelve computers around a central hub.A
A product from Adobe Systems Inc. for manipulating documents, stored in proprietory Portable Document Format (PDF). Acrobat provides a platform-independent means of creating, viewing, and printing documents.
Anonymous FTP server - a server with a repository of files for public access over the Internet. To use such a server, connect with FTP, and log in as anonymous using your electronic Email address as a password.
Applet - A type of computer program that allows animation and other interactive functions on a file or Web page.
Application - Software that carries out tasks on a computer so that you can write documents, make drawings and pictures, view remote Web sites and send or receive mail over the Internet.
Archive - a general term used to refer to long term storage. An archive could consist, for example, of all the messages sent within a discussion group since its start, a collection of images or other documents.
Argument - a piece of data that is passed to a subroutine within a program. The argument could be the value of the data or the address at which it may be found.
ARIN - American Registry for Internet Numbers a non-profit organization that registers and administers IP numbers for North America, part of the Caribbean and sub-Saharan Africa as one of four regional Internet registries.
Array - a method of storing a series of pieces of data so that each may be retrieved using a programmable variable, which for a series of pieces of data, refers to an individual piece.
Attachment - email messages sent over the Internet can have a computer file attached to them, for example, a text or word-processed document or an image file.
Authentication - method of accessing Internet or intranet resources which requires the user to enter a username and password.
Average page views per period - the average number of page views on a site for the period.
Average page views per visitor - the number of pages each visitor to a site views on average.
Average unique visitors per period - the average number of people who visit a site during a period.
Average visits per visitor - the average number of times each unique visitor visits a site. The average reflects all traffic for the time period of the report.
Backbone - the top level in a hierarchical communications network.
Backdoor - a surreptitious or secret method of gaining access to a computer through a network. Access mechanisms of this sort may be included by systems developers without the knowledge of the end user, or may be present for legitimate maintenance reasons.
Backup - to make a copy of data to ensure its security in the event of disk failure, accidental deletion etc. Also used to refer to the security copy itself.
Bandwidth - the rate that data (information) travels from one place to another either inside a computer or between computers through a communications circuit, usually expressed as bits per second (bps), kilobits (thousands of bits) per second (kbit/s), megabits (millions of bits) per second (Mbit/s).
Bandwidth Shaping - bandwidth allocation - management of a network's connection to control the amount of bandwidth available to different activities. Commonly used by ISP's to limit consumption of bandwidth by users.
Batch - automatic scheduling and execution of programs to perform a repetitive task many times without user interaction. For example, batch processing may be used to convert a large number of images from one format to another.
BBS - Bulletin Board System - a public access meeting place on the Internet allowing people to carry on discussions, make announcements and download files.
Bézier Curve - invented by Pierre Bézier (1910 - 1999) French engineer - a method for modelling smooth curves used in drawing, typesetting and fontography software, generally using a minimum of three points to define a cubic mathematical function. Each end of the curve is located at an anchor point with one or more nodes in between defining the shape of the curve. Nodes can be moved individually and the direction of the curve passing through each node is defined by control points attached to the node.
Binary - the method of encoding information (1s and 0s) into digital bits.
Bit - the smallest piece of binary (1s and 0s) digital information understood by computers. Stands for Binary DigIT. The actual speed at which you send information via your computer is measured in bits per second (bps), as in 64,000bps (or 64kbit/s) with a digital line. A 28.8 modem allows for a connection of 28.8 kilobits per second.
Blended threats - use multiple methods and diverse technologies such as viruses, worms, trojan horses & malware to attack a computer system or network and spread the attack, taking advantage of hardware and software vulnerabilities. By mounting an attack using several methods at the same time, blended threats spread rapidly, often automatically without user input, and maximise the damage done. The intention is malicious.
Blocking software - a computer program that allows people who think that they know best (parents, teachers, or guardians) to "block" access to certain Web sites and other information available over the Internet. All blocking software has filtered the information before blocking access to it. (See also "filtering software")
Bookmarks - a stored note of the address of interesting or frequently used Web sites, so that these sites can be revisited easily without having to remember or retype the Internet address. Most web browsers allow you to store the names and addresses of Web sites enabling you to return to them. In some browsers the address list is called 'Favourites'.
Bottom up- a design philosophy where a programming solution is produced from a library of functions, macros or subroutines which perform individual common functions. This method allows rapid assembly of a program but is liable to produce unwieldy code. The opposite of top down.
Buffer - a temporary storage area for data, often provided to improve performance.
Bug - a programming error in a computer program which can cause unwanted side effects such as incorrect calculations, program or systems instability, failure or freezing, security problems.
Button - a small graphic, like the "about your browser" one just above, placed on a web page to advertise or indicate a link to another resource.
Byte - a unit of memory or data needed to represent one character in binary (1s and 0s) form. One byte was 8 bits on older computers, followed 16 bit systems. 32 bit systems computing is the current standard for most PCs.
Cache - part of your computer's volatile memory or an area of non-volatile storage on your hard drive. Web browsers store information (text, graphics, sounds, etc.) from pages or sites that you have visited recently in your hard drive cache, so that when you return to those pages or sites the information appears much faster.
Cascading style sheets - (CSS) - a method for adding 'styles' such as fonts, colour and positioning to web pages, while separating style markup from content.
CD-ROM - an optical computer disk that can store large amounts of information (typically 600 Mbytes) which can be read by computers with CD-ROM drives. "CD-ROM" stands for "Compact Disk Read Only Memory". That means it can only play back information, not record or save material. Read-Write drives are becoming common, and use special blank discs.
CFML - Cold Fusion Markup Language.
Character - a letter of the alphabet, number, punctuation mark or other symbol, usually entered into a document by pressing a key on the keyboard. Some documents include invisible, non-printing characters to control formatting.
(e.g. A a B b C c ... X x Y y Z z 0 1 2 3 4 5 6 7 8 9 # £ $ % : , " + [ > ... are all examples of characters.)
Chat - a popular feature of online services or Web sites that allows participants to "talk" by typing messages that everyone can read at the same time. The participant logs on to the chat room, types a message on his computer keyboard, sends it, and it is instantly displayed on the screens of the other users in the chat room. Admission is generally not restricted. As one never knows who is going to be reading the messages or responding to them, it's best to avoid revealing personal details.
Chat room - a public access meeting place or page on a Web site or online service where people can chat, or "talk," with each other by typing messages on their computer keyboard. This is a system of "real-time" communication like talking on the phone, except that the "talkers" are typing text.
Client - the browser used by a visitor to a web site.
Client-based filter - a software program that you install on your own computer to block access to material that you consider inappropriate, prevent children from accessing the Internet at certain times, or to prevent children from revealing personal information. See also "filtering software" and "blocking software."
Coaster - slang term for an optical disc that has been ruined during an attempt to write to it, often caused by buffer under-runs. Also any defective, malfunctioning or unwanted optical disc.
Code generation - synonymous with compilation.
Commercial service - general term for large online services which provide access to the internet and other services for a monthly or annual fee. Some commercial services try to attract members by providing "added value" in the form of content, games, and chat rooms that are available only to subscribers.
Compiler - A utility which converts the source code of a program in a high level language (e.g. Basic, Pascal, C) into a executable machine code file. A compiled program runs faster, and is usually smaller, than the source program executed via an interpreter.
Computer language - a set of rules and systems of symbols for writing computer programs which control the computer.
Concatenate - joining two things together by adding the start of the second to the end of the first. Concatenation my be performed on two strings of characters, files, records etc.
Constant - a value (e.g. Pi=3.14159265), asigned to a symbolic name, which does not change throughout the execution of a computer program. See: Variable.
Contention ratio - a mechanism used by some Internet Service Providers to share internet connectivity between a number of access services the aggregate bandwidth of which, is higher than the bandwidth of the connection to the internet. This mechanism is generally used with entry level services.
Contiguous - of data stored continuously without any gaps. Similarly, of a file where the disk sectors storing the file are physically next to each other on the disc.
Control keys - of special keys on a keyboard which modify the action of other keys when pressed at the same time.
Cracker - a person who who breaks a security system, and/or in some cases maliciously damages computer systems, for example by launching a Denial of Service (DoS) attack. Not to be confused with hacker, although the words are often interchanged in common parlance.
Crippleware - is computer software made freely available to demonstrate operation of a programme, but severly limited in functionality so that little meaningful work can be done. After registration, a key is provided to unlock the software and remove limitations.
Crosstalk - a phenomenon where signals from one circuit can contaminate other circuits, potentially degrading their performance.
CSMA/CD - Carrier Sense Multiple Access / Collision Detection - is a method used to control multiple access to a shared transmission medium. A station waits for quiet on the medium before starting to transmit and listens to the signals on the transmission medium while the message is being transmitted. If this is different from the signal being transmitted, a collision is said to have occurred and been detected. The station then ceases transmission and retries again later.
Cyberloafer - cyberslacker - slang term for an employee who surfs the internet, composes and sends email and carries out other internet-related activities unrelated to the employer's business and during time for which the employer is paying wages.
Cyberspace - a very general modern term used variously in colloquial speech:
i. as a reference to the electronic areas and communities on the Internet and other computer networks;
ii. the culture developing on (or across) the global network of communications media that make up the Internet;
iii. a new publishing or communications medium separate from conventional media;
iv. and a "place" separate from or in addition to physical space.
Data type - of a variable according to the type of data it contains e.g. BOOLEAN, FLOATING POINT, INTEGER, STRING.
Delimiter - one or more characters used to separate objects in a list, computer program etc.
Device - any component or assembly used for a specific purpose e.g. disc drive, modem, terminal.
Device driver - a system dedicated to controlling a specific device, interfacing between the device and main the software.
Disk Cache - dedicated RAM used to speed up access to a hard disc which may be a reserved area of the general RAM (soft disk cache) or part of the disc drive (hard disc cache). The latter is more effective in improving peformance by storing the most recently accessed data so that the computer can access it fater than by reading the disc directly.
Discussion group - an area online focused on a specific topic where users can read and add or "post" comments ("post" in the sense of posting something on a bulletin board or sending email to an email list). You can find discussion groups, also referred to as "discussion boards," for almost any topic. Some groups are organised as email distributions systems, where messages sent to the host server are re-distributed to multiple email addresses of those persons subscribed to the group. See also "Newsgroups".
Directories - virtual folders used to organise data and information.
i. used to hold or organise collections of files usually related by content or type.
ii. similar to search engines. Directories are indexes of web pages organised by subject.
Domain name - all computers accessing the Internet have a unique IP (Internet Protocol) number, cross-referenced with a unique domain name usually followed by a domain suffix .com, .org or .co.uk (e.g. 'succulent-plant.com'). The domain name is a user-friendly way of referring to the IP number.
Domain name System (DNS) - a set of protocols and services on the Internet that allow use of hierarchical user-friendly names to refer to other hosts (i.e. computers) instead of having to remember and use their IP address numbers.
Download - copying a data file from a remote computer to your own. "Download" is also used to mean viewing a Web site, or material on a Web server, with a Web browser.
Duty Cycle - of a printer or copier is the number of prints or copies that the device can produce reliably on a monthly basis. If the duty cycle is exceeded regularly, the reliability of the equipment may be compromised. However, if subtantially fewer impressions are made per month, the equipment has been over-specified and a cheaper alternative could have been purchased.
DVD - Digital Versatile Disk - high capacity CD ROM that will only work with a computer fitted with a DVD drive. Holds up to 4.7 Gigabytes of information, the equivalent of 7 CD ROMs.
EIDE - (fast ATA, ATA-2, fast IDE) an abreviation for Enhanced IDE, an updated version of the IDE mass storage device interface standard developed by Western Digital Corporation. Various flavours of EIDE support data rates of 4 - 16.6 MBps, 3 - 4 times faster than the old IDE standard. Ultra-ATA (Seagate Technologies) supports data transfer rates up tp 33 Mbps. EIDE supports mass storage devices of up to 8.4 gigabytes; IDE was limited to 528 MB. EIDE is often found as a more cost-effective replacement for SCSI.
Email - Electronic mail - the modern method of sending messages electronically over the Internet. Messages usually consist of plain text, with documents and multimedia documents usually sent as attachments. Users need a telephone line connected via a modem to their computer, and an e-mail address (recognisable because of the "@" symbol, with a typical format: email@example.com). Numerous service providers offer free email accounts.
Encryption - encoding or "scrambling" of messages for security purposes which makes them difficult for unauthorised people to read. Security services tend to dislike encryptation wich is too good (secure), since they think that they should be able to read everybody's messages.
Equipment failure - physical or functional failure of a piece of equipment in such a way as to impair its performance.
Equipment overload - an excessive load placed on a piece of equipment, which may lead to failure or degraded performance.
Error - A failure of software or hardware to carry out a particular function.
Error message - A displayed or printed text reporting a software or hardware error or fault and usually providing diagnostic information about the error. See also web server errors
Ethernet - the name of the the most common technology for connecting computers together in a local area network invented at the Xerox Corporation Palo Alto Research Centre. It operates using the CSMA/CD medium access control.
e-waste - a trendy term for "electronic waste", the result of discarded electronic devices. Many consumer electronic devices are discarded after a short time by users due to technological advances, low cost of replacement and uneconomic cost of repair. Much electronic waste is contaminated by toxic substances such as lead, mercury and cadmium and so is often classified as hazardous waste.
Expression - a group of numbers and symbols that may be evaluated to give a value.
Extranet - private external website on the Internet, which can only be accessed by authorised persons. Usually applied to a company site which is accessible to customers, partners, suppliers or distributors.
FAQ - Frequently Asked Questions - about a particular Internet site or service, usually a page created by the Webmaster to provide answers to common problems or queries. It is a good idea to read the FAQ list before sending messages to the service provider, especially if you are new to the site.
File - a collection of related records, treated as a single unit and referenced by a single filename.
Filtered ISP - an Internet Service Provider (ISP) that automatically blocks access to content that they consider to be inappropriate for children or others. The content that is blocked depends on the particular company's criteria, which may be different from your own.
Filtering software - software that sorts and classifies information on the Internet according to content. Some software allows the user to make personal choices about which sort of information should be blocked.
Firewall - a security device that places a protective "wall" around a computer or network of computers, keeping it from being accessible to the public. This is typically used to protect an internal network when it is connected to an outside network, especially the Internet, so that a cluster of more loosely administered computers are protected from hackers and other unauthorised access.
Flaming - the act of sending an offensive e-mail to an individual or discussion group or posting an offensive comment in a newsgroup or bulletin board, usually in response to a posting that offended someone. Flaming may be grounds for exclusion or withdrawal of service by some ISPs.
Flash - a proprietory technology, from Macromedia Inc., which allows Web page developers to create animated navigation interfaces, technical illustrations and impressive moving effects, while maintaining a compact file size.
Flexible Working - a system of working without the constraints of time or location and gives organisations the freedom to determine the best ways to complete tasks.
Fried - of electronic hardware that has been destroyed by excessive voltage, heat or other environmental problems.
Front end - a software user-interface designed to provide easy access to more complex software. See: GUI
FTP - File Transfer Protocol - allows a user on one computer to transfer ("download" or "upload") files to and from another computer over a TCP/IP network. Commonly used to transfer files from a computer hard drive to update a Web site on a remote server.
Freeware - is computer software that the author makes available without charge, while retaining the copyright, rights to control distribution, modify the software and sell it at a later date. The term "Freeware" was trademarked in the 1980s by Andrew Fluegelman, an attorney, computer magazine editor and software developer (e.g. PC-Talk. ) After the trademark ceased to be maintained, the term became generic.
Function - a subroutine that returns a value when called from the main program.
Gateway - generally applied to any device that provides access to another system. Also applied to a hardware device that connects a local network to the Internet. ISPs are sometimes referred to as "gateways" to the Internet
GIF - Graphic Interchange Format - a standard file format that supports graphics compression, allowing the graphics to be viewed on most computers and Web browsers.
Gigabyte - a billion bytes (1024 megabytes).
Gopher - A menu based service that enables you to navigate through Internet information. Predecessor of the World Wide Web.
Graphics - the use of lines, figures and shapes to display information.
Graphics accelerator - A dedicated card or integrated circuit chip that fits inside your computer which will speed up its graphics performance, by relieving the central processor of the task of displaying graphics output. In some computers, graphics accelerator chips are built into the motherboard. This allows you to watch more realistic 3D images, real-time video and games.
GUI - Graphical User Iinterface - a user-friendly front end to a computer to provide access to the underlying software.
Hacker - a person who enjoys exploring the details of programmable systems and maximisation of their capabilities. Hacker should not be be confused with cracker, although the term hacker is widely, and incorrectly, used in this context.
Hacktivism - ("hack" + "activism") the activity or promotion of computer hacking as a politically or socially motivated means of expression. The primary motivation of the Hacktivist is to draw attention to a cause by web-based civil disobedience, rather than to cause harm or gain financially. An example would be to modify a website to convey a message of opposition to that normally displayed or to the operations of the website's owners.
Hardware - The electronic integrated circuitry etc of a computer and computer-related equipment. Also used to refer to the whole computer and related machines such as scanners and printers.
High level language - A computer programming language that is relatively machine independent and attempts to increase user-friendliness by use of commands in English, instead of machine code. Examples of high level languages are: BASIC, C, FORTRAN, PASCAL.
Home page - The first or main page you usually see when you enter a website.
Hot link - reference link on a website that takes you straight to another website at the click of your mouse button.
HTML - HyperText Markup Language - the most common computer mark-up language used to create web pages on the World Wide Web. Now a de-facto universal standard.
Hyperlink - Link on a web page (image or portion of text) that takes you straight to another page at the same or another site. Text hyperlinks are usually a different colour from the rest of the text, underlined, or both. If it's an image, you can tell it's a hyperlink if you see a border around it, or if the cursor changes to a little hand when you drag the cursor over the image with the mouse. You just click on the link to go to another Web page or another place on the same page. See also links.
HTTP - HyperText Transfer Protocol. The protocol used for transferring hypertext files on the web.
Interactive - A process requiring a diaglogue between the user and computer.
Internet - A global network of computers inter-connected by communications media.
Interpreter - A software utility that executes an source program in a high level language (e.g. BASIC) without the need for its compilation. However, an interpreted program runs much more slowly than when compiled.
IP - Internet Protocol. A communications technology that enables movement of data from one network to another.
Intranet - A private internal website usually only accessible by members of an organisation through passwords or by physical isolation.
IP Address - The 32-bit numerical address defined by Internet Protocol, cross-referenced with a unique domain name. It is usually represented in dotted decimal notation ( four numbers separated by dots ). The IP address uniquely identifies every site on the Internet, but the domain names are more usually used to reference Web sites.
ISDN - Integrated Services Digital Network - A super-fast technology that allows a higher speed internet connection over a standard telephone line than a 56k modem allows. The line can be used for two services at once, such as two Internet connections or an Internet connection and a telephone line. The technology is older and the connection speed lower than with ADSL.
ISP - Internet Service Provider - an organisation which provides Internet access, usually for a fee. ISPs may be distinguished from commercial services, which link to the Internet but also offer additional services, such as content and chat, only available to their subscribers.
Iterative - a procedure or section of code that repeats a group of instructions.
Java - a proprietory programming language invented by Sun Microsystems that allows development of platform independent applications, such as calculators. The language was developed to allow programs to be written and downloaded through the Internet without fear of viruses; however, this requires strict attention to security aspects. Using small Java programs, or 'Applets', it is possible to incorporate a variety of dynamic features in a web page.
JPEG - A widely-recognised file format for compressing and storing images, allowing the graphics to be viewed on most computers and Web browsers. Significant artefacts may be generated around sharp edges at high compression ratios, and thus text fonts may be badly degraded.
Journaled File System - a method of maintaining data integrity on a hard disk drive in the event of a system failure. The system maintains a log or journal of all data activity on the disc with updates to data written to a serial log. In the event of a failure, any lost data can be recovered from the log and data restored to the pre-crash configuration.
Keylogging - use of covertly installed software or hardware to record keystrokes on a computer. This may be used to covertly monitor employee efficiency and sometimes for dishonest purposes where passwords and credit card numbers are collected.
Keyword - On search engines, keywords are typed into the search form, or search "window," to search for files, pages or sites that contain your keyword and information related to it.
Kilobyte - a measure of the size of a data file. A kilobyte is 1,024 bytes.
LAN - Local Area Network - allows several computers near to each other, usually in the same office, to share data, information and peripheral equipment such as printers.
LCS - Liquid Cooling System - a method of cooling energy-intensive integrated circuits such as microprocessors. Cool liquid is pumped in a closed loop circuit through small bore piping into a special heatsink attached to the processor, removing waste heat and releasing it to the air at a remote radiator. LCS systems offer more efficient cooling and less noise than air-cooled systems, but are more complex to install and requires more maintenance.
Lexical analysis - the breakdown of a document into its constituents based on type and value.
Link - highlighted text that includes a reference to another document, Web page, or Web site, so that clicking on the link makes the browser load the referenced document.
LINX - London INternet eXchange - a not-for-profit partnership between Europe's Internet Service Providers. Established in 1994, the LINX has two main functions: to provide a physical interconnection for Service Providers to exchange Internet traffic in the UK through co-operative peering agreements and, secondly, to further the cause of the UK Internet in Europe. LINX membership is open to all Internet Service Providers owning a permanent, independent, international connection to the Internet. LINX currently represents the interests of 44 Internet Service Providers.
Log file - a data file created by a web or proxy server which contains the access information regarding the activity on that server.
Longitudinal Recording - a mode of recording data to a hard disc drive where data bits are aligned horizontally in relation to the track on the spinning platter.
Low level language - a computer language capable of accessing machine instructions directly.
Macro - Computer keystroke short-cut command that makes life easier by automating various commonly performed tasks.
Macro Virus - A program or code that replicates by infecting another program or document that supports macros by inserting itself or attaching itself to that medium.
Malware - computer software which includes software that infiltrates or damages a computer system, often without the owner's knowledge. The term includes a variety of ad-ware and computer viruses that come packaged with apparently useful software.
MaNAP - Manchester Network Access Point - a neutral peering point based in Manchester providing an Internet exchange service for any ISP operating in the UK. MaNAP is an ISP owned exchange point with an open membership policy. It is intended to provide a useful service to regional and national ISPs alike. MaNAP is the UK's second peering point, the LINX was the first.
Megabyte One megabyte is a million bytes (1024 kilobytes).
Memory - any device capable of storing information for subsequent recovery.
Microbrowser - mobile browser - mini-browser. A cut-down version of a web browser designed for use on small screens such as found on WAP-based mobile phones and other mobile devices.
Microprocessor - the hardware within a computer responsible for processing data.
Modem - A hardware device that connects a telephone line to a computer, allowing what is generally referred to as "dial-up access". The higher the modem speed, up to a current maximum of 56K (or 56 kilobits per second), the faster the data are received or transmitted.
Monitoring software - allows a parent or caretaker to monitor the Web sites or e-mail messages that a child visits or reads, without necessarily blocking access.
Mouse - a small hand-held device, attached to your computer by wire, wireless or infra-red, which allows control of the computer cursor by moving the mouse on a surface. Commands can be given to the computer by clicking the device button(s) while the cursor is positioned over a button or link.
MPEG - Moving Pictures Experts Group - MPEG-1 is optimised for CD ROM, MPEG-2 for broadcast quality video and MPEG-4 for low bandwidth video telephony.
Multimedia - combined use in a presentation of two or more types of data such as text, graphics, images audio, and video.
Nagware - is computer software provided for demonstration purposes, or to provide basic limited functionality, which includes systems to produce messages or pop-up windows nagging the user to purchase the full product.
NAT - Network Address Translation. A hardware device currently being developed and used to extend the Internet addresses already in use.
Netiquette - generally recognised rules of civil behaviour as applied to the Internet (discussion groups, chat rooms etc.). Manners are usually enforced exclusively by the responses and attitudes of fellow users.
Newsgroups or USENET- The exchange of messages over the Internet organised by subject within USENET. Outside USENET these exchanges are called discussion groups. Discussion groups consist of messages sent by Internet users and displayed publicly for everyone in the group (or under the topic area) to read. Newsgroups are distinct from news services or journalism.
New visitors - the number of visitors viewing a site for the first time.
i. of a computer disconnected from the internet.
ii. of equipment or devices not currently under direct control of the computer.
OFTEL - Office of Fair Trading for TELecommunications.
i. of a computer connected to the internet.
ii. of equipment or devices under direct control of the computer.
Operating system - Software that makes your computer function. Often abreviated to OS. Macintosh OS 10.2 is an up-to-date, user-friendly operating system. Many personal computers use a version of Windows overlying a version of MS-DOS, and other independent manufacturers have their own proprietory operating system.
Optical fibre - An ultra-thin strand of special high quality glass, usually protected with a plastic sheath, capable of transmitting billions of bits of information a second.
Organization - a suffix to a Domain name indicating the type of organisation owning the domain or the country associated with the site. Typical suffixes are:
.ac = Academic
.com = Commercial
.edu = Educational
.int = International
.gov = Government
.mil = Military
.net = Network
.org = Organization
Packet sniffers - are programs that monitor data traveling over TCP/IP networks. Packet sniffers are very powerful tools that can be inserted anywhere on the network to monitor traffic going by, and hence can be very dangerous tools in the wrong hands.
Page views - also called Page Impressions. Only hits to HTML pages are counted.
PDF - Portable Document Format. Proprietory file format developed by Adobe Systems to allow display and printing of PDF-formatted documents across diverse platforms and systems. PDF files can be read on any system equipped with the Acrobat Reader software.
Peering - an arrangement between two Internet service providers, which allows them to share traffic as "peers", by direct connection to each other's networks without having to pass through other networks. This provides an advantage by eliminating intermediate connections in the routes that transfer the data, and increasing access speed.
Peripheral - synonymous with device.
Pharming - fraudulent redirection of net users from legitimate to fake web sites, usually for dishonest purposes.
Phishing - use of fraudulent e-mail messages and web page pop-ups designed to fool users into revealing personal information to third parties for dishonest purposes.
PICS - Platform for Internet Content Selection - is a technology that allows Web browsers to read content ratings of Web sites, but it is not a rating system itself.
PictBridge - allows direct printing of images from a digital camera on a printer without using a computer to handle or control the process. PictBridge is an industry standard so enables hardware from different manufacturers to communicate, with uniform error messages.
Ping - Packet INternet Groper - is a small program used to test connectivity and functionality of remote destinations by sending them one, or multiple echo messages and waiting for replies. If an Internet host receives a PING request it will send a response to the originator. Since PING works at the IP level it is often implemented entirely within the operating system kernel and is thus pretty much the lowest level test of whether a remote host is alive. PING will often respond even when higher level protocols cannot. Conversely, if there is no PING response it is unlikely that a higher level protocol will work.
Platform - the operating system (Macintosh, Windows 95, Windows NT, etc.) used by a visitor to a web site.
Plug-in - a program that works with browsers, graphics, imaging and other programs to add extra functions not provided by the original software.
Pointer - a small item of data that indicates the location of another item of data.
PoP - Point of Presence - a number which is dialed to connect to an Internet Service provider.
POP3 - Post Office Protocol 3 - is the most recent version of the standard protocol for receiving email. POP3 is a client/server protocol in which email is received and held for you by your Internet Service Provider. Periodically, you or your client email receiver, check your mail-box on the server and download any mail.
Port Scanning - uses special software which allows the user to scan the computer system of another Internet user. The purpose of this can include obtaining passwords and usernames, remotely controlling that computer, or altering/destroying data on that computer.
PPP - Point-to-Point Protocol - allows a computer to use TCP/IP to connect to other computers over a standard telephone line using a high-speed modem.
Processor - (microprocessor) the hardware within a computer responsible for processing data.
Protocol - an established method of exchanging data between computers or over the Internet.
PSTN - Public Switched Telephone Network - a circuit-switched analogue network which makes connections for the duration of a telephone call. These connections are usually used for voice but can also carry data between facsimile machines and computers (via a modem).
Qubit - or Qbit - a quantum bit, unit of quantum information in a 2-level quantum mechanical system where the information is in a superposition of the two states. On measurement, the information collapses into the state determined by the probability of the qubit being in each state. Hence multiple measurements are needed to obtain a reliable answer.
Quantum entanglement allows the quantum state of a pair of particles that have interacted, and separated by at any distance, to be correllated. Measurement of the quantum state of one particle in the pair immediately determines that of the other particle to be in the opposite state.
RAM - Random Access Memory - is the volatile memory that a computer uses to store data, including executable program files and the operating system, for its main operation. The more RAM you have installed in your computer, the more applications and larger data files that can be used at the same time. Adding more RAM will not by itself increase the speed of a computer, but may appear to do so because less time is wasted swapping applications in/out of RAM. The data in RAM is lost when the computer is turned off.
Recursive - of a procedure that can call itself.
Referrer - the URL of an HTML page that refers visitors to a site or to the current page. Some browsers allow the referrer of the last page visited to be retrieved from the property: document.referrer
Remote Access - Allows access to most of the services which would be available on a computer or network, which is accessed over a modem link. The service includes support for dialup and password logon, and then presents the same user interface as seen when directly connected.
Remote Login - working on a remote computer, using a protocol over a computer network, as though locally attached - for example, logging in to a computer or network at work from home via a modem.
Resilience - The ability of a system to continue operation, despite failure of a primary system or link, by switching to a secondary circuit. This concept is used to provide robust Internet connectivity where Internet traffic is automatically routed through a secondary circuit linked to a different service node from the primary circuit, in the event of a break in service of the primary circuit.
Resource Record - A Domain name System is made up of one or many master files. Master files are referred to as zone files, and contain information specific to a domain in the form of Resource Records. Resource records contain all data associated with a particular node, which can have 0 to n resource records associated with it.
Returning visitors - the number of visitors who have previously visited and returned to a site.
RFID - Radio Frequency IDentification - a method of identifying objects by use of small RFID transponders attached or embedded in each item. RFID chips incorporate a silicon chip with embedded ID number and other data and an antenna to enable them to receive radio-frequency interrogation and respond with their unique identifier. Passive tags obtain all their power from the radio-frequency interrogator while active tags, responding over a greater range, include their own power source.
Rogue Access Point - any Wi-Fi access point installed on a network that is not authorized for operation on that network, and is not under the management of the network administrator. Rogue access points may not conform to wireless LAN (WLAN) security policies, and can allow anyone with a Wi-Fi device to connect to the network.
Rogue dialler - a program that installs itself covertly on computers and changes modem settings to dial and connect to the internet via a premium rate number instead of the usual dial-up account.
Routing - The process, performed by a router or gateway, of selecting the correct interface and next hop for a packet of data being forwarded to a remote destination.
RSACi - Recreation Software Advisory Council's Internet rating system for Web content that uses PICS technology. RSACi was recently renamed the Internet Content Rating Alliance (ICRA).
Scalable - a quality of a solution that allows it to grow as the usage of the service increases.
ScreenTip - ToolTip - graphical user interface (GUI) feature where a small text box appears when a mouse pointer is placed over an icon or button. The pop-up box usually provides an explanation of the icon or button's function and disappears when the pointer is moved away.
Secure Transactions - A recent development for commercial use of the Internet, which allows the safe encoded transmission of financial details, credit card numbers and other information across the Internet or an Intranet.
Security - Provision of secure access onto the Internet from your network and prevention of unauthorised Internet users from outside your network accessing your information and computing resources.
Semantics - the definition of the meaning of the various symbols and strings of symbols in a programming language or web document.
Server - a computer which provides remote data storage and other facilities such as email for multiple users who connect via a network or by remote access. An example would be the computer at an Internet Service Provider which your computer (referred to as a 'client') connects to when you link on to the Internet or to update Web pages.
Server Farm - server cluster - computer farm / ranch - a group of networked servers housed in a single location, distributing the workload between individual machines using load-balancing software. A server farm is resistant to failures of individual components as other machines take over its function.
Shareware - is computer software that you are able to copy from a remote location and try out before having to purchase it. Payment is made on an 'honour' basis, but may be enforced by limited functionality or time-out limitations on unregistered versions of the software. Sending a small registration fee to the author is often required to obtain a "key" to unlock some functionality and remove messages exhorting the user to register. Shareware is relatively inexpensive as it is often provided by an enthusiast with minimal packaging or advertising expenses. You cannot sell a shareware product, but you can pass on the intact package to others, who are also expected to pay the registration fee.
SMTP - Simple Mail Transfer Protocol - used to send email across the Internet.
Software - a computer program, made up from a set of instructions, also called "computer code", to be loaded into your computer's memory and executed (run) to carry out a task. System software contains the instructions to operate the machine itself (such as the MacOS operating system), and "application software" carries out specific tasks (applications) such as word processing or drawing graphics.
Source code - the original plain text form of a computer program prepared by a programmer, often in a high level language such as 'C', C++, Basic, Fortran, Pascal. The source program is compiled to make an executable programme, or in some languages can be run immediately via an interpreter.
Spam - an inappropriate, often annoying or unpleasant, use of email where the same unwanted message is sent to lots of people, often to email addresses gathered at random from the Internet. This often comes in the form of unsolicited "junk" e-mail containing advertising or promotional messages sent to large numbers of people. Sometimes people or companies send sexually explicit unsolicited e-mail, known as "porn spam." Spam is clearly distinguished from multiple messages sent to subscribers to newsletters, discussion groups etc. where the recipients have requested the mail. The origin the term is obscure but may be derived from a cult 1970's Monty Python sketch where the word 'spam' was repeated again and again.
Spider - a software program that "crawls" through the Web, jumping from page to page via active links, searching through Web sites and indexing their pages into a database that can be searched using a search engine.
Spyware - small programs, often covertly installed with legitimate software, that secretly monitor sites visited and report back to a remote host, potentially violating user security and, by stealing processor time, slowing execution of legitimate tasks.
SQL - Structured Query Language - used by many professional relational databases for data access and management.
SSL - Secure Socket Layer - a protocol developed by Netscape for the secure transmission of sensitive documents over the Internet. SSL uses two keys - a public key known to everybody and a private key known only to the recipient. Many web sites use SSL to encrypt transmission of confidential user information, such as credit card numbers. Breaking the encrypted code is feasible but requires huge computational power and would take too long to be of practical use.
Streaming - the broadcasting of sound and video over an Intranet or Internet in real time.
String - a contiguous collection of characters.
Suffix - the part of a Domain name indicating the type of organisation owning the domain or the country associated with the site. Typical suffixes are:
.ac = Academic
.com = Commercial
.edu = Educational
.int = International
.gov = Government
.mil = Military
.net = Network
.org = Organization
Syntax - the set of rules governing the structure of statements in a programming language or web document.
i. Use of keywords (tags) used to categorise web pages, images, blogs etc which can be indexed by online search services.
ii. Use of RFID labels on consumer items. iii. Use of radio-transmitters, RFID tags and other physical markers to identify individual members of wildlife.
TCP/IP Transmission Control Protocol/Internet Protocol - a system which guarantees that all computers, wherever they are and with numerous different operating systems, can connect to one another via the Internet. If you're reading this online, your computer has TCP/IP software.
TELNET - a program which allows you to log in to other computers on the Internet and access information or run software. Most firewalls will bar TELNET entry. It is the Internet standard protocol for remote terminal connection to a host computer.
Terminal adapter - a device that connects your computer to a digital communications line, allowing you to communicate over the Internet, by phone or fax.
text - a collection of one or more strings of characters.
Thumbnail - a miniature preview representation of a page or image, which will download and render much faster than the full file.
Time limiting software - allows expiry time limits to be set for access to the Internet or applications such as games. After the expiry time, the software no longer functions or has a reduced function.
Top down - a design philosophy where a programming solution is designed and constructed in a systematic and controlled manner. The opposite of bottom up.
Trialware - Demoware - is computer software provided for the purposes of demonstration, which can be run for a limited period of time or number of activations, after which it ceases to operate without a registration key.
Trojan horse - an apparently useful software program containing hidden functions that can exploit the privileges of the authorised user [running the program], with a resulting security threat. A Trojan horse does things that the program user did not intend. Trojan horses rely on users to install them as part of the software package, or they can be installed by intruders who have gained unauthorised access by other means. An intruder attempting to subvert a system using a Trojan horse relies on authorised users running the application, containing the Trojan horse, at a later time to activate the hidden function. A Trojan Horse may arrive by email but relies on the user to activate it by attempting to run the program containing the virus.
Tunnel - Tunnelling is used to get data between administrative domains which use a protocol that is not supported by the Internet connecting those domains.
Unique visitors - the number of people who viewed a site during any given period of time. Not to be confused with Active Visitors.
Upload - Copying a data file from your own computer to a remote one, such as a remote web server.
USENET - Newsgroups - A world-wide system of discussion groups, indexed according to subject, which allow comments to be passed between large numbers of computers.
URL - Uniform Resource Locator - a standard form of reference for the unique address of any site or page on the World Wide Web. URLs typically have four parts: Protocol Type (HTTP), Machine name (succulent-plant.com), Directory Path (/other/), and File name (index.html). Hence: http://www.succulent-plant.com/other/index.html
Variable - a value asigned to a symbolic name, which can assume any value during execution of a computer program. See: Constant.
Virtual device - a device which exists only in software, but gives the impression of being a discrete physical object such as a disc.
Virtual host - (vhost) - a provider of web services such as server disc space and internet connections to those who do not wish to provide their own hardware.
Virus - an unwanted program that replicates itself on computer systems by copying itself and incorporating itself into other programs which are shared between computers on a network. Almost any executable code with read-write priviledges is vulnerable. Some viruses are relatively harmless "jokes" that have benign but annoying effects on the infected computer such as changing the display, writing an alarming message etc. In other cases, the virus may also be programd to do additional damage. Some viruses replicate quietly with no obvious symptoms, but may activate destructively on a particular date. There are also a variety of virus hoaxes propagated from user to user by email like a chain letter, which describe the horrendous consequences of infection by a supposedly new virus. There is no attachment: the message is the virus which relies on the user to propagate it.
Viruses subclasses include:
Macro, Trojan Horse, Worm.
Visit - the sequence of activities for one user of a web site. A unique visitor is determined by the cookie and can be tracked in this way. By default, a visit is terminated when a visitor is inactive for more than 30 minutes. Synonym: Session.
VPN - Virtual Private Network - the use of encryption in the lower protocol layers to provide a secure connection through an otherwise insecure network, typically the Internet. VPNs are generally cheaper than real private networks using private lines but rely on having the same encryption system at both ends. The encryption may be performed by firewall software or possibly by routers.
WDM - Wave Division Multiplexing - transmission of data simultaneously on multiple carrier wave lengths (or frequencies). WDM provides a way to increase the transmission capacity by using multiple channels at different frequencies.
Web - The World Wide Web - actually just one of the services on the Internet, is a collection of graphical hyperlinked documents made publicly available on computers (or Web servers) around the world. The documents on these servers can be viewed or accessed with a browser.
Web-based chat - as opposed to chat IRC found on subscriber-only online services, Web-based chat allows people to chat with each other using a browser. Web-based chat rooms are found in Web sites.
Web-based E-mail - browser technology for sending and receiving E-mail (e.g. Netscape) as opposed to a separate E-mail software program (e.g. Eudora).
Web-based Instant-Messaging - Instant-Messaging technology that works in Web sites (as opposed to a commercial online services).
Webmaster - the person responsible for administering, managing and often designing a Web site.
Web Scraping - processesing the HTML of a web page with an application programme that extracts data for further manipulation such as convertion of the Web page to another format (i.e. HTML to WML).
Web site - a group of related web pages, typically, owned by a single company, organisation or person.
Web server - the computer a web site resides on:
A web server can host more than one web site. A large web site can be distributed between more then one web server.
i. Write Once Read Many - applied to many CD-ROM disks that only allow a single data writing operation but can be read indefinitely. Some newer types of blank CD-ROM disks allow multiple write operations in a suitable disk drive.
ii. a type of computer virus. that makes copies of itself, from one disk drive to another, or between computers by using email and network resources. A worm may damage computer files and exploit security loopholes. Worms can arrive by email as a joke program or attached to software which activates them when the user clicks on it or may exploit security loopholes in client. software and self-activate when an email is opened.
WWW - World Wide Web - The Web - a collection of graphical hyperlinked documents made publicly available on computers (or Web servers) around the world. The documents on these servers can be viewed or accessed with a browser.
Xon-xoff - A communications protocol used to synchronise modems and similar devices.
Zip drive - An internal or external computer drive with removable high
capacity disks (from 100Mb up) that enable you to organise, move and back up data files.