Glossary of Internet Terms [A-D]

[Kalyan]

Glossary of Internet Terms [A-D]

A

ADN -- (Advanced Digital Network)
Usually refers to a 56Kbps leased-line.

ADSL -- (Asymmetric Digital Subscriber Line)
A DSL line where the upload speed is different from the download speed. usually the download speed is much greater.

Applet
A small Java program that can be embedded in an HTML page. Applets differ from full-fledged Java applications in that they are not allowed to access certain resources on the local computer, such as files and serial devices (modems, printers, etc.), and are prohibited from communicating with most other computers across a network. The common rule is that an applet can only make an Internet connection to the computer from which the applet was sent.

Archie
A tool (software) for finding files stored on anonymous FTP sites. You need to know the exact file name or a substring of it. By 1999 Archie had been almost completely replaced by web-based search engines. back when FTP was the main way people moved files over the Internet Archie was quite popular.

ARPANet -- (Advanced Research Projects Agency Network)
The precursor to the Internet. Developed in the late 60's and early 70's by the US Department of Defense as an experiment in wide-area-networking to connect together computers that were each running different system so that people at one location could use computing resources from another location.

ASCII -- (American Standard Code for Information Interchange)
This is the defector world-wide standard for the code numbers used by computers to represent all the upper and lower-case Latin letters, numbers, punctuation, etc. There are 128 standard ASCII codes each of which can be represented by a 7 digit binary number: 0000000 through 1111111.

B

Backbone
A high-speed line or series of connections that forms a major pathway within a network. The term is relative as a backbone in a small network will likely be much smaller than many non-backbone lines in a large network.

Bandwidth
How much stuff you can send through a connection. Usually measured in bits-per-second. A full page of English text is about 16,000 bits. A fast modem can move about 57,000 bits in one second. Full-motion full-screen video would require roughly 10,000,000 bits-per-second, depending on compression.

Baud
In common usage the baud rate of a modem is how many bitsit can send or receive per second. Technically, baud is the number of times per second that the carrier signal shifts value - for example a 1200 bit-per-second modem actually runs at 300 baud, but it moves 4 bits per baud (4 x 300= 1200 bits per second).

BBS -- (Bulletin Board System)
A computerized meeting and announcement system that allows people to carry on discussions, upload and download files, and make announcements without the people being connected to the computer at the same time. In the early 1990's there were many thousands (millions?) of BBS?s around the world, most are very small, running on a single IBM clone PC with 1 or 2 phone lines. Some are very large and the line between a BBS and a system like AOL gets crossed at some point, but it is not clearly drawn.

Binary
Information consisting entirely of ones and zeros. Also, commonly used to refer to files that are not simply text files, e.g. images.

Binhex -- (BINary HEXadecimal)
A method for converting non-text files (non-ASCII) into ASCII. This is needed because Internet e-mail can only handle ASCII.

Bit -- (Binary DigIT)
A single digit number in base-2, in other words, either a 1 or a zero. The smallest unit of computerized data. Bandwidthis usually measured in bits-per-second.

BITNET -- (Because It's Time NETwork (or Because It's There NETwork))
A network of educational sites separate from the Internet, but e-mail is freely exchanged between BITNET and the Internet. Listservs®, a popular form of e-mail discussion groups, originated on BITNET. BITNET machines are usually mainframes running the VMS operating system, and the network is probably the only international network that is shrinking.

bps -- (Bits-Per-Second)
A measurement of how fast data is moved from one place to another. A 56K modem can move about 57,000 bits per second.

Browser
A Client program (software) that is used to look at various kinds of Internet resources.

BTW -- (By The Way)
A shorthand appended to a comment written in an online forum.

Byte
A set of Bits that represent a single character. Usually there are 8 Bits in a Byte, sometimes more, depending on how the measurement is being made.

C

CATP -- (Caffeine Access Transport Protocol)
Common method of moving caffeine across Wide Area Networks such as the Internet
CATP was first used at the Binary Cafe in Cybertown and quickly spread world-wide.
There are reported problems with short-circuits and rust and decaffinated beverages were not supprted until version 1.5.3

Certificate Authority
An issuer of Security Certificates used in SSL connections.

CGI -- (Common Gateway Interface)
A set of rules that describe how a Web Server communicates with another piece of software on the same machine, and how the other piece of software (the CGI program) talks to the web server. Any piece of software can be a CGI program if it handles input and output according to the CGI standard.

cgi-bin
The most common name of a directory on a web server in which CGIprograms are stored.

Client
A software program that is used to contact and obtain data from a Server software program on another computer, often across a great distance. EachClient program is designed to work with one or more specific kinds of Server programs, and each Server requires a specific kind of Client. A Web Browser is a specific kind of Client.

co-location
Most often used to refer to having a server that belongs to one person or group physically located on an Internet-connected network that belongs to another person or group. Usually this is done because the server owner wants their machine to be on a high-speed Internet connection and/or they do not want the security risks of having the server on their own network.

Cookie

The most common meaning of "Cookie" on the Internet refers to a piece of information sent by a Web Server to a Web Browser that the Browser software is expected to save and to send back to the Server whenever the browser makes additional requests from the Server.

Depending on the type of Cookie used, and the Browsers' settings, the Browser may accept or not accept the Cookie, and may save the Cookie for either a short time or a long time.

Cookies might contain information such as login or registration information, online "shopping cart" information, user preferences, etc.

When a Server receives a request from a Browser that includes a Cookie, the Server is able to use the information stored in the Cookie. For example, the Server might customize what is sent back to the user, or keep a log of particular users' requests.

Cookies are usually set to expire after a predetermined amount of time and are usually saved in memory until the Browser software is closed down, at which time they may be saved to disk if their "expire time" has not been reached.
Cookies do not read your hard drive and send your life story to the CIA, but they can be used to gather more information about a user than would be possible without them.

Cyberpunk

Cyberpunk was originally a cultural sub-genre of science fiction taking place in a not-so-distant, dystopian, over-industrialized society. The term grew out of the work of William Gibson and Bruce Sterling and has evolved into a cultural label encompassing many different kinds of human, machine, and punk attitudes. It includes clothing and lifestyle choices as well.
See also: Cyberspace

Cyberspace
Term originated by author William Gibson in his novel Neuromancer the word Cyberspace is currently used to describe the whole range of information resources available through computer networks.

D

Digerati

The digital version of literati, it is a reference to a vague cloud of people seen to be knowledgeable, hip, or otherwise in-the-know in regardsto the digital revolution.

Domain Name

The unique name that identifies an Internet site. Domain Names always have 2 or more parts, separated by dots. The part on the left is the most specific, and the part on the right is the most general. A given machine may have more than one Domain Name but a given Domain Name points to only one machine. For example, the domain names:

can all refer to the same machine, but each domain name can refer to no more than one machine.
Usually, all of the machines on a given Network will have the same thing as the right-hand portion of their Domain Names (matisse.net in the examples above). It is also possible for a Domain Name to exist but not be connected to an actual machine. This is often done so that a group or business can have an Internet e-mail address without having to establish a real Internet site. In these cases, some real Internet machine must handle the mail on behalf of the listed Domain Name.

DSL -- (Digital Subscriber Line)

A method for moving data over regular phone lines. A DSL circuit is much faster than a regular phone connection, and the wires coming into the subscriber's premises are the same (copper) wires used for regular phone service. A DSL circuit must be configured to connect two specific locations, similar to a leased line (howeverr a DSL circuit is not a leased line.

A common configuration of DSL allows downloads at speeds of up to 1.544 megabits (not megabytes) per second, and uploads at speeds of 128 kilobits per second. This arrangement is called ADSL: Asymmetric Digital Subscriber Line.
Another common configuration is symmetrical: 384 Kilobits per second in both directions.
In theory ADSL allows download speeds of up to 9 megabits per second and upload speeds of up to 640 kilobits per second.

DSL is now a popular alternative to Leased Lines and ISDN, being faster than ISDN and less costly than traditional Leased Lines.