A Plain Language Glossary
of Internet terminology,
its component technologies,
with associated abbreviations and acronyms
A--F

 
     

Address
An address is the unique identifier assigned to each web site and its constituent pages. The words of that address --- www.somesite.co.uk --- are invisibly converted to a four-group number string -- eg 208.56.54.98 -- which  in fact is what the browser reads and searches for. (see DNS below) This address forms part of what is known as the URL. Immediately after a browser begins its search for a web site, it displays -- very briefly -- that site's number-string in the status bar as 'Connecting to...208.56.44.43.' before 'Finding www etc...' and 'Opening www etc...' appear.

ADSL
Asymmetric digital subscriber line. DSL technology allows the twisted, copper wires which are the basis of the telephone network to carry significantly more information per second. It works by using the unused bandwidth on an existing telephone line. Analogue transmission is noisy; digital transmission is precise. (The difference is similar to that between AM and digital radio where AM tuning spreads, while the digital is spot on the designated wavelength.) This technology permits high-speed multimedia services like VoD, also high-speed Internet access, remote corporate LAN and videoconferencing, for anyone with access to a copper line. On an ordinary analogue telephone line, signals are limited to (an ideal) 56 kbps. After the digital connection is installed and DSL technology is used, the same line can provide data rates over a real Mb per second -- ie 1024 kbps or 20 times the analogue rate.

ANSI
American National Standards Institute. A voluntary organisation which creates standards for the computer industry; also electrical specifications and some communications-related protocols.

AOL
America OnLine. Large, international ISPs such as AOL and CompuServe provide 'content' in addition to access to the Internet. This content is mostly information: weather, the stock market, sport and just about everything else which can be formatted usefully in a world pursued and driven by the Information Furies.

Apache
The open-source software currently used on the majority of HTTP web servers ie close to 60% (May 2000). Microsoft software is used on about 20% of servers. Increasingly, Apache (www.apache.org) is being used in conjunction with Linux, a version of Unix which remains the most popular; Sun Microsystems's Solaris takes second place. Netscape's share is in single figures. Apache is public domain software; as is Linux. see: GNU Appendix
Source of usage figures: www.netcraft.com/survey/

Applet
A small application often written or embedded in DHTML or JavaScript or the Java language which works on a web page. It can be an animation or sound, or a mouse-over. Java is a kind of computer Esperanto since it is OS non-specific. The colour change when the mouse moves over this button [a mouse-over] is Java enabled. Other common applets are image rollovers, scrolling text, display of random images. These applets are viewable only in Java-enabled browsers: however, 99% of browsers in use are so enabled.

Anonymous FTP
Anonymous file transfer protocol. It is a simple procedure to gain access to a remote server using FTP without the need of being registered with that server or site. Academic sites and large companies and corporations like Microsoft and Intel maintain such repositories with vast quantities of material.  Other large file-sources such as SimTel, SunSite, Winsite and euronet are also stacked to the rafters with freeware and shareware for all platforms. They are excellent sources for the more arcane aspects of computing; often where command-line rules OK. A user's e-mail address is commonly used as the password; the user name 'anonymous' is given for the ordinary visitor. The rest of the site may well be accessible only by more secure procedure on private folders/directories. Usually, public access is limited to folders with names like 'pub' -- ie public. Among the more well-known programs utilising this protocol are Cute FTP, FTP Explorer (which is freeware) and WS_FTP.

Archie
A program which searches all anonymous FTP sites for specific files. It can be used in conjunction with a browser; it can also respond to an e-mail which names the file[s] required and, once it has succeeded, it will obligingly return an e-mail with the results of its labours.

Archive
The word 'archive' generally refers to large compressed files; often they will contain several smaller files -- for instance, an executable with its associated files which together comprise an application. The most frequently-used archive types are ZIP, ARJ (below). Also used are LZW and tar. Text files can be reduced to 30% of their original size which is highly desirable; images, such as jpg or gif, are scarcely affected since they are compressed already.

ARJ
A compression format named after its deviser, Robert Jung; similar in function to ZIP. It works well compressing databases and large documents.

ARP
Address resolution protocol. It is used in TCP/IP to link an IP address to a precise physical address, ie a stand-alone work-station or a work-station in a network.

ARPA
Advanced Research Projects Agency -- of the US Department of Defense -- is responsible for developing new technologies of use to the armed forces. It developed ARPANET (1968) -- a research and secure communications network -- which became the foundation of what is now known as the Internet.

ASCII
American Standard Code for Information Interchange. This is the code which is used to represent alpha-numeric characters in binary code. It is used in plain text files which have minimal formatting and are very economical with space ie bytes. For example, a Microsoft Word 97 document containing 216 words [1291 characters] takes up 19,968 bytes. The same document in Ascii takes up 1291 bytes ie plain text uses one byte per character. This is why e-mail attachments are best sent as Ascii text: they go in a twinkling while Word 97 documents stagger on seemingly forever. For most users, using word processors for letters and so on, there are 127 ASCII characters. There are more but these have specialised functions which are not pertinent here.

ATM
Asynchronous transfer mode. A communications standard that can transfer data at up to 155 Mbps using an ISDN link.. It is designed to transmit voice and video, and other multimedia data that must be broadcast in 'real time'. That process is known as 'streaming'. British Telecom has seen fit to implement ISDN at only a fraction of its potential speed yet still charge as if it ran at full speed. This pricing structure is likely to be echoed and amplified when ADSL emerges later this year, 2000.

Attachment
A file, separate from the message -- body -- text, which is appended to ie 'attached' to an e-mail. It can be text, an image, a sound, video, etc. Frequently, applications are sent as attachments but when this is done they are/should be zipped to reduce transmission time. However, attachments can  be dangerous as recent virus alarms have shown: Melissa last year, ILOVEYOU and others this. The basic wisdom is never open an attachment unless you are certain you know who it's from and it is expected. As the ancient psalm has it, 'Beware the attachment, for it may plant itself in thy bosom and inscribe thy heart with poison, cloud the windows of light and destroy the settings of peace..' It is a cliché but clichés can and do bite. The recent .vbs scripts sown with nasties have served only to emphasise the well-known potential for damage in e-mail attachments. 

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Backbone
The high-speed, high-bandwidth connection path to which smaller sub-networks are attached. The motorway in other words. Most home users are on four-figure A roads; the unlucky are on B roads. There is always congestion somewhere; also, physical components  -- routers, servers, switches, varieties of access modules, exchanges, even -- however reliable, do break down. Thus the 'off-line' message from your ISP with its brief apology. Activity on the Internet is often referred to as 'traffic'; in fact, there are web sites which display logs and chart of such 'traffic', reporting congestion etc.

Bandwidth
Bandwidth is measured as the amount of information one channel is able to send per second. The more the merrier. That is why a web page loads so much faster from a PC's hard drive web cache than it does from a web server: bandwidth. A frequent misconception is that a faster CPU results in faster downloads: this quite erroneous -- a notion often promoted by salesmen intent on pushing needlessly high-speed chips. The speed of the CPU counts only after the modem has passed data to it. Metaphorically, bandwidth is the amount of water coming out of your tap: its maximum delivery is limited ultimately by its dimensions, and the water pressure -- ie bandwidth. No pressure: no water (however fat the tap); low pressure: a trickle. The modem is a tap: the flow into the bath has nothing to do with the bath itself, a one-person job or an ocean. The faster the modem (56K, rather than 33K) the better it can take advantage of high bandwidth. Hence the high expectations and anticipation at the prospect of ISDN and ADSL which are not subject to the travails of the suffering analogue modem and its frustrated owner. Nevertheless, the heart of the analogue-connection problem is that it is sensitive to just about everything which might and can interfere with its signal. Somewhere there is always 'noise' of some kind, or interference as we hear on the radio or see on our TV screens. (After all, about 10% of the snowy dots we see on a blank TV screen are echoes -- even now -- of the Big Bang!) The digital signal is immune and oblivious.

Baud [rate]
Speed at which data is transferred by a modem. More precisely, one baud equals one bit per second [bps] in a string of binary signals. Therefore, in theory, the Word 97 document mentioned above, would take one second to download at the ideal 56,000 bps; while its Ascii cousin would take 0.02 seconds. Modems today range nominally up to 56,000 bps. In practice, a steady 40,000-44,000 bps is very good fortune and much to be desired.

BBS
Bulletin Board System. It is in essence an electronic messaging database with enables people to leave messages for general viewing; messages are then posted in reply. The system allows 'threads' or themes/topics to be established and followed by anyone with appropriate software. There are many BBSs throughout the world and they should not be confused with newsgroups. A BBS is frequently run by an individual with a special interest and or by hobbyists.

Binary 
A number representation system, base 2, consisting of 0 and 1 -- distinct from decimal which is base 10. It is used by all computers for its ease of use in digital electronics. When the term is used to refer to file formats it indicates the file is a sequence of bits, not plain text. Some plain examples of alphabet and number are below. Note that letters and numbers share the same binary notation. (It's visually easier to read if the strings are split into two groups of four digits. In practice, there are no spaces.)

Bit
Binary digIT. The smallest, irreducible, unit of computerised data, represented by either a 1 or 0. A combination of bits can indicate an alphabetic character, a numeric digit, or perform a signaling, switching or other function. Bandwidth is usually measured in bits-per-second. It has been suggested that an earlier form of the word was 'bigit'.

Bitmap [.bmp]
Any image constructed from a 'map' of bits each of which is coded (or 'impregnated') with colouring information. BMPs, JPGs, (or JPEG) and GIFs are all bitmaps; the latter two use some form of compression to reduce their size. A BMP photograph can be 999,954 bytes in size while the same picture in Gif form takes 239,473 bytes, and its Jpg form requires only 46,435 bytes using a standard 75% compression. [Figures based on a real photograph of Io, one of Saturn's moons.] A bitmap's file extension is .bmp. The other form of images used on the web are vectors which are mathematically defined -- start and endpoint, colour information etc; therefore they can be enlarged as much as one likes without loss; whereas a bitmap has a defined number of pixels which make up the picture: too much enlarging and definition is lost to large pixels, rather than a larger image. Flash animations/images are all vector based.

BITNET
One of the first and now largest wide-area networks, mainly used by American universities. It has been replaced by version II which uses the Internet as its communications network.

Body
That part of an email which contains the actual message. The Header and Signature are not usually displayed, being an apparent jumble; but they are well worth looking (a few times anyway) since they show the route and timings of the e-mail's journey to its recipient.

Bookmark
Computer bookmarks in documents serve the same purpose as those in books. They record a URL or position on a web page, enabling the user to refer back and forth. Properly known as hyperlinks, they are an intrinsic element of the Internet - allowing easy movement back and forth; in small, they are used throughout this glossary for all cross-referencing. For instance, each [Top of page] which takes you to the top of its page is a bookmark or hyperlink; so also is the reference, two lines above, to URL in this item -- since it takes you to that definition. They are, in effect, abbreviated addresses.

bps
bit(s) per second. See bit above. The unit of measure for the speed at which modems transfer data.

Browser
Also  'web browser'. A software program which enables a user to search the Web and other Internet facilities using a GUI. The most commonly used browsers [Spring/Summer 2000] are Microsoft Internet Explorer and Netscape Navigator. The bundling by Microsoft of Internet Explorer with Windows 95/98 prompted the US Justice Dept to investigate Microsoft for abuse of its dominant position and bullying. The grounds for this pretext rather than other Microsoft practices is not clear: Netscape squealed loudest, others joined in. Navigator was probably not as good as IE at the time; Netscape cried 'Foul!' That it was more politics than law is fairly clear -- regardless of the merits of the claims about Microsoft's bad practice. However, the browser war is long over -- IE won hands down -- and the law suit seems rather irrelevant now. This takes some piquancy from the fact that Netscape now rests in the ample bosom of first AOL and now Time/Warner.

Byte
A data unit consisting of 8 bits which usually represents one letter or digit.

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C
A high-level programming language developed at Bell Labs in the 1970s: it was the language used to write Unix. C is both powerful and flexible with an additional advantage of not requiring much computer memory; for these reasons it is also popular with PC programmers.

CERN
Conseil Européen pour la Recherche Nucléaire. It is the European laboratory for particle research where immense particle accelerators are used to crack open these vanishingly small physical entities -- leptons, quarks, with charm and the posited Higgs' boson. It is also more pertinently here where the basic protocols for the WWW were written by Tim Berners-Lee, now recognised as father or architect of the Internet. This work was prompted by the need of scientists to be able to exchange and share information quickly and easily. T B-L is also director of W3C.

CGI
Common gateway interface. A standard which runs programs for a web server.  There is a special 'cgi.bin'  to which web pages refer for implementation. For example, after a request to a database for information the server will format the answer in HTML allowing it to be read easily by a browser. CGI scripts can be written in C (above), Java, Perl and Visual Basic.

Client
In a client-server relationship, the client is a computer which applies for programs or applications stored on the server, or which accesses files from it.

CompuServe
Formerly known as CompuServe Information Services. One of the first and largest and now international ISPs. It was bought by AOL in 1997. Unlike the majority of ISP which provide only access to the Internet, CompuServe has a great many databases which its customers may make use of.

Cookie
A cookie is a small text file which holds brief information about you. Usually it just records the fact that you have visited a particular web site. This enables a web site to 'recognise' you --  its server peeks into your cookies folder -- when next you go back. (They are not nor is their intention malicious but like most things they can in theory be malign.) For example, if you register with a site, when you return it might greet you by using your user-name as it says 'Hello..' or whatever. That is one way a cookie works. If you don't want them, then you can easily crumble them by using one of the many programs which block them.

Cybercafé
A café or bar giving customers access to the WWW while having a cup of coffee or snack. Charges are customarily per hour of machine time. aka Internet café.

Cybernym
A term coined to cover words and also acronyms and abbreviations dealing with the computer and the telecommunications industries.
see: Elsevier's Dictionary of Cybernyms at the publisher's web site

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Daemon
Daemons are used mostly on Unix systems. They wait for a particular 'event' before they become active. 'Cron' is one Unix daemon which executes a pre-set command or sequence of commands at a specified time.

DHTML
Dynamic HTML. In essence, the term refers to web-page content which is dynamic ie which has mobile elements or can responds to the user. JavaScripts and CGI can produce such dynamic effects. However, when written as DHTML, the term refers to extensions or enhancements to HTML scripts which can produce animation effects or respond to a user without recourse to a web server. The final specifications will be determined by W3C.

Dial-up
Sometimes known as dial-up access. A dial-up account involves a computer using a modem literally to dial-up the telephone number of an ISP to gain access to the Internet.
see: Modem

Domain name
The name -- an IP address -- which identifies each unique web site as in 'www.yoursite.co.uk' -- where 'yoursite' is the name, and the 'co.uk' suffix is the top-level domain (TLD) to which it belongs.
see IAHC

Domain name server
A computer whose function it is to keep track of the IP addresses and domain names of other machines. It is to this server that the browser first refers when seeking a web site, taking the Ascii domain name and converting it to its numeric form, its real IP address. 
see: IP Address

Domain name system [DNS]
The system by which the address typed into the browser's address field is converted into a numeric form which can be executed as a command to open the requested pages.

DOS
Disk operating system.  DOS can, strictly speaking, refer to any operating system using a disk. However, it is commonly used to refer to Microsoft's DOS, MS-DOS. originally, it was developed by Bill Gates for IBM's personal computer (which became the 'template' for the generic PC as used today). DOS is a 16-bit OS and was superseded by the 32-bit Windows 95. However, DOS remains functional on all Windows machines as a sometimes-useful legacy.

DoS
Denial of service is an attack on a server or system of servers or network intended to put them out of action by overwhelming them with unmanageable numbers of requests. There are fixes for different kinds of attack, but the hackers responsible are ever ingenious with new methods.

Download
The action of transferring a file between two computers using the Internet. The remote machine connected to the Internet often uses anonymous FTP from which you download onto your local machine. Also, HTTP is used and can frequently be much faster; another advantage of using HTTP is that a GUI is used, whereas FTP uses a plain file tree, as in Windows Explorer. Often, though, one has no choice in the matter as the process is determined by whoever made the software available. There are many programs available which can meter and display download and upload rates, both commercial and shareware/freeware.
see: Upload

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e-mail, electronic mail
An electronic message in plain, unformatted text which is sent to another location to be received at an e-mail address often based upon the domain name of the ISP the recipient uses. Free web-based e-mail accounts are increasingly used: Hot Mail was bought by Microsoft; Yahoo and other similar organisations also offer free e-mail.
see : Attachment, Body, Header, Signature

Emoticon
A smile or frown created from keyboard symbols :) often used in email to suggest emotions (emote + icon) -- hence the name. Their use is tiresome.
see: Smiley

Ethernet
A LAN protocol developed in 1976 by Xerox, DEC and Intel. It is the most commonly-used of LAN standards and can transfer data at up to 10Mb per second. A more recent version can transfer data at up to one GB a second.

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FAQ
Frequently asked question. FAQs and their answers are found all over the WWW. They are usually found on software makers' sites, hardware manufacturers' and other sites where technical information is found. They permit users to search for answers to questions which have already been resolved; they also save software companies the labour of endlessly answering the same question from new users of their products.

FDDI
Fibre distributed data interface. A standard set of ANSI protocols for sending data through optical-fibre cables at up to 100 Mbps (100 million bits per second).
see: Bandwidth, Ethernet, T-1/T-3

Filename extension
Usually a three-letter extension (sometimes it is two or four letters) attached to a file name indicating its type. Just about everywhere software product has its own file type: .doc is a Microsoft Word document, .js is a JavaScript file, .dos is DOS text information, .pcl is a Hewlett Packard control language file etc etc. Two common examples which can be used by a variety of programs are: .txt for text files, .gif  for a Graphics Interchange Format file.

Finger
A Unix program which displays information about a particular user or all users logged on to a system; it uses e-mail addresses as the search item. This facility is now common in PC e-mail programs.

Firewall
Secures a company or organisation's internal network from unauthorised external access (most commonly in the form of Internet hackers).

Flame
To 'flame' a person is to send an insult by e-mail usually to a newsgroup or bulletin board in response to a breach of good manners or 'netiquette'. Such exchanges, involving several people, are often hot-tempered affairs which is when they become known as a 'flame war'. The phlegmatic are naturally insusceptible to such occasions but if involved should get themselves a new e-mail account, since flame wars can result in hot pursuit.

Flash
A Macromedia program much used by web designers. It uses vector images rather than bitmaps: these are mathematically based and therefore require considerably less space. Flash animations are very effective and can be dramatic and entertaining. Frequently though, they merely display expertise without great purpose. The viewer is forced to wait for the page to finish loading and often these pages are so dense they take a long time to download. When finished -- if the viewer has not moved on elsewhere -- one has to press Enter to go further. All that time just to Enter! The well-publicised crash of boo.com (May, 2000) highlighted the disadvantages of too much technology on a site: many visitors could get no further than the opening page. For anyone without the most recent browser and plug-ins, nothing could be bought and the site was unusable. It's worth adding that one day all web sites will use boo.com's highly technical approach and they will be easily navigable. boo.com's misfortune was that they were too early -- apart from any financial and management woes.

Forms
The bane of all bureaucratic societies; sadly the Internet is not immune. Current browsers support on-line forms. A form on a web page can be used to register for extra facilities available on a site; or to submit a request to receive a newsletter by e-mail. Such forms need a CGI program for processing.

Freeware
Software made available by the author for free distribution on the Internet. Usually, the only conditions attached are that the program not be modified or charged for at any time. Public domain software, GNU, and other closely-related matters are dealt with separately and extensively in their own individual entries. However, there is a clear distinction to be made between programs published by individuals and available without charge and programs distributed under the auspices of the Gnu distribution licence. 'Free software' refers to the users' freedom to run, copy, distribute, study, change and improve the software; whereas the majority of other free software may not be 'changed or improved in any way' -- although its distribution is unhindered. It is a matter of philosophy. See, in particular, the documents in the Gnu appendix.
see: Public Domain, Shareware; see also the Gnu Appendix

FTP
The file transfer protocol is one of the two ways files are transferred over the Internet. FTP sites are often provided by companies and organisations as archives of files for free download.
see: Anonymous FTP above

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