Glossary of Internet Terms

ADN: (Advanced Digital Network) -- Usually refers to a 56Kbps leased-line.
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.
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 that would survive a nuclear war.
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 15,000 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 bits it 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).
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. Bandwidth is usually measured in bits-per-second.
Bps: (Bits-Per-Second) -- A measurement of how fast data is moved from one place to another. A 28.8 modem can move 28,800 bits per second.
Browser: A Client program (software) that is used to look at various kinds of Internet resources.
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.
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. Each Client 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 thier 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 Browser’s 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 user’s 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.
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.
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:

matisse.net
mail.matisse.net
workshop.matisse.net

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.
E-mail: (Electronic Mail) -- Messages, usually text, sent from one person to another via computer. E-mail can also be sent automatically to a large number of addresses (Mailing List).
Fire Wall: A combination of hardware and software that separates a LAN into two or more parts for security purposes.
Flame: Originally, flame meant to carry forth in a passionate manner in the spirit of honorable debate. Flames most often involved the use of flowery language and flaming well was an art form. More recently flame has come to refer to any kind of derogatory comment no matter how witless or crude.
FTP: (File Transfer Protocol) -- A very common method of moving files between two Internet sites. FTP is a special way to login to another Internet site for the purposes of retrieving and/or sending files. There are many Internet sites that have established publicly accessible repositories of material that can be obtained using FTP, by logging in using the account name anonymous, thus these sites are called anonymous ftp servers.
Gigabyte: 1000 or 1024 Megabytes, depending on who is measuring.
Gopher: A widely successful method of making menus of material available over the Internet. Gopher is a Client and Server style program, which requires that the user have a Gopher Client program. Although Gopher spread rapidly across the globe in only a couple of years, it has been largely supplanted by Hypertext, also known as WWW (World Wide Web). There are still thousands of Gopher Servers on the Internet and we can expect they will remain for a while.
hit: As used in reference to the World Wide Web, “hit” means a single request from a web browser for a single item from a web server; thus in order for a web browser to display a page that contains 3 graphics, 4 “hits” would occur at the server: 1 for the HTML page, and one for each of the 3 graphics.

“hits” are often used as a very rough measure of load on a server, e.g. “Our server has been getting 300,000 hits per month.” Because each “hit” can represent anything from a request for a tiny document (or even a request for a missing document) all the way to a request that requires some significant extra processing (such as a complex search request), the actual load on a machine from 1 hit is almost impossible to define.
Home Page (or Homepage): Several meanings. Originally, the web page that your browser is set to use when it starts up. The more common meaning refers to the main web page for a business, organization, person or simply the main page out of a collection of web pages, e.g. “Check out so-and-so’s new Home Page.”

Another sloppier use of the term refers to practically any web page as a “homepage,” e.g. “That web site has 65 homepages and none of them are interesting.”
Host: Any computer on a network that is a repository for services available to other computers on the network. It is quite common to have one host machine provide several services, such as WWW and USENET.
HTML: (HyperText Markup Language) -- The coding language used to create Hypertext documents for use on the World Wide Web. HTML looks a lot like old-fashioned typesetting code, where you surround a block of text with codes that indicate how it should appear, additionally, in HTML you can specify that a block of text, or a word, is linked to another file on the Internet. HTML files are meant to be viewed using a World Wide Web Client Program, such as Netscape or Mosaic.
HTTP: (HyperText Transport Protocol) -- The protocol for moving hypertext files across the Internet. Requires a HTTP client program on one end, and an HTTP server program on the other end. HTTP is the most important protocol used in the World Wide Web (WWW).
Hypertext: Generally, any text that contains links to other documents - words or phrases in the document that can be chosen by a reader and which cause another document to be retrieved and displayed.
Internet: The vast collection of inter-connected networks that all use the TCP/IP protocols and that evolved from the ARPANET of the late 60’s and early 70’s. The Internet now (July 1995) connects roughly 60,000 independent networks into a vast global internet.
Intranet: A private network inside a company or organization that uses the same kinds of software that you would find on the public Internet, but that is only for internal use.

As the Internet has become more popular many of the tools used on the Internet are being used in private networks, for example, many companies have web servers that are available only to employees.; See Also: Internet, Network
IP Number: (Internet Protocol Number) -- Sometimes called a dotted quad. A unique number consisting of 4 parts separated by dots, e.g.

165.113.245.2

Every machine that is on the Internet has a unique IP number - if a machine does not have an IP number, it is not really on the Internet. Most machines also have one or more Domain Names that are easier for people to remember.
IRC: (Internet Relay Chat) -- Basically a huge multi-user live chat facility. There are a number of major IRC servers around the world which are linked to each other. Anyone can create a channel and anything that anyone types in a given channel is seen by all others in the channel. Private channels can (and are) created for multi-person conference calls.
ISDN: (Integrated Services Digital Network) -- Basically a way to move more data over existing regular phone lines. ISDN is rapidly becoming available to much of the USA and in most markets it is priced very comparably to standard analog phone circuits. It can provide speeds of roughly 128,000 bits-per-second over regular phone lines. In practice, most people will be limited to 56,000 or 64,000 bits-per-second.
ISP: (Internet Service Provider) -- An institution that provides access to the Internet in some form, usually for money.
Kilobyte: A thousand bytes. Actually, usually 1024 (2^10) bytes.
LAN: (Local Area Network) -- A computer network limited to the immediate area, usually the same building or floor of a building.
Leased-line: Refers to a phone line that is rented for exclusive 24-hour, 7 -days-a-week use from your location to another location. The highest speed data connections require a leased line.
Listserv®: The most common kind of maillist, "Listserv" is a registered trademark of L-Soft international, Inc. Listservs originated on BITNET but they are now common on the Internet.
Maillist: (or Mailing List) A (usually automated) system that allows people to send e-mail to one address, whereupon their message is copied and sent to all of the other subscribers to the maillist. In this way, people who have many different kinds of e-mail access can participate in discussions together.
Megabyte: A million bytes. Actually, technically, 1024 kilobytes.
Mirror: Generally speaking, “to mirror” is to maintain an exact copy of something. Probably the most common use of the term on the Internet refers to “mirror sites” which are web sites, or FTP sites that maintain exact copies of material originated at another location, usually in order to provide more widespread access to the resource.

Another common use of the term “mirror” refers to an arrangement where information is written to more than one hard disk simultaneously, so that if one disk fails, the computer keeps on working without losing anything.
Modem: (MOdulator, DEModulator) -- A device that you connect to your computer and to a phone line, that allows the computer to talk to other computers through the phone system. Basically, modems do for computers what a telephone does for humans.
Mosaic: The first WWW browser that was available for the Macintosh, Windows, and UNIX all with the same interface. Mosaic really started the popularity of the Web. The source-code to Mosaic has been licensed by several companies and there are several other pieces of software as good or better than Mosaic, most notably, Netscape.
Netscape: A WWW Browser and the name of a company. The Netscape (tm) browser was originally based on the Mosaic program developed at the National Center for Supercomputing Applications (NCSA).

Netscape has grown in features rapidly and is widely recognized as the best and most popular web browser. Netscape corporation also produces web server software.

Netscape provided major improvements in speed and interface over other browsers, and has also engendered debate by creating new elements for the HTML language used by Web pages -- but the Netscape extensions to HTML are not universally supported.

The main author of Netscape, Mark Andreessen, was hired away from the NCSA by Jim Clark, and they founded a company called Mosaic Communications and soon changed the name to Netscape Communications Corporation.

See Also: Browser, Mosaic, Server, WWW
Network: Any time you connect 2 or more computers together so that they can share resources, you have a computer network. Connect 2 or more networks together and you have an internet.
Node: Any single computer connected to a network.
Packet Switching: The method used to move data around on the Internet. In packet switching, all the data coming out of a machine is broken up into chunks, each chunk has the address of where it came from and where it is going. This enables chunks of data from many different sources to co-mingle on the same lines, and be sorted and directed to different routes by special machines along the way. This way many people can use the same lines at the same time.
POP: (Point of Presence, also Post Office Protocol) -- Two commonly used meanings: Point of Presence and Post Office Protocol. A Point of Presence usually means a city or location where a network can be connected to, often with dial up phone lines. So if an Internet company says they will soon have a POP in Belgrade, it means that they will soon have a local phone number in Belgrade and/or a place where leased lines can connect to their network. A second meaning, Post Office Protocol refers to the way e-mail software such as Eudora gets mail from a mail server. When you obtain a SLIP, PPP, or shell account you almost always get a POP account with it, and it is this POP account that you tell your e-mail software to use to get your mail.
PPP: (Point to Point Protocol) -- Most well known as a protocol that allows a computer to use a regular telephone line and a modem to make TCP/IP connections and thus be really and truly on the Internet.
Router: A special-purpose computer (or software package) that handles the connection between 2 or more networks. Routers spend all their time looking at the destination addresses of the packets passing through them and deciding which route to send them on.
Server: A computer, or a software package, that provides a specific kind of service to client software running on other computers. The term can refer to a particular piece of software, such as a WWW server, or to the machine on which the software is running, e.g.Our mail server is down today, that’s why e-mail isn’t getting out. A single server machine could have several different server software packages running on it, thus providing many different servers to clients on the network.
SLIP: (Serial Line Internet Protocol) -- A standard for using a regular telephone line (a serial line) and a modem to connect a computer as a real Internet site. SLIP is gradually being replaced by PPP.
SMTP: (Simple Mail Transport Protocol) -- The main protocol used to send electronic mail on the Internet.

SMTP consists of a set of rules for how a program sending mail and a program receiving mail should interact.

Almost all Internet email is sent and received by clients and servers using SMTP, thus if one wanted to set up an email server on the Internet one would look for email server software that supports SMTP.
Spam (or Spamming): An inappropriate attempt to use a mailing list, or USENET or other networked communications facility as if it was a broadcast medium (which it is not) by sending the same message to a large number of people who didn’t ask for it. The term probably comes from a famous Monty Python skit which featured the word spam repeated over and over. The term may also have come from someone’s low opinion of the food product with the same name, which is generally perceived as a generic content-free waste of resources. (Spam is a registered trademark of Hormel Corporation, for its processed meat product.)

E.g. Mary spammed 50 USENET groups by posting the same message to each.
T-1: A leased-line connection capable of carrying data at 1,544,000 bits-per-second. At maximum theoretical capacity, a T-1 line could move a megabyte in less than 10 seconds. That is still not fast enough for full-screen, full-motion video, for which you need at least 10,000,000 bits-per-second. T-1 is the fastest speed commonly used to connect networks to the Internet.
T-3: A leased-line connection capable of carrying data at 44,736,000 bits-per-second. This is more than enough to do full-screen, full-motion video.
TCP/IP: (Transmission Control Protocol/Internet Protocol) -- This is the suite of protocols that defines the Internet. Originally designed for the UNIX operating system, TCP/IP software is now available for every major kind of computer operating system. To be truly on the Internet, your computer must have TCP/IP software.
URL: (Uniform Resource Locator) -- The standard way to give the address of any resource on the Internet that is part of the World Wide Web (WWW). A URL looks like this:

http://www.matisse.net/seminars.html
or telnet://well.sf.ca.us
or news:new.newusers.questions
etc.

The most common way to use a URL is to enter into a WWW browser program, such as Netscape, or Lynx.
USENET: A world-wide system of discussion groups, with comments passed among hundreds of thousands of machines. Not all USENET machines are on the Internet, maybe half. USENET is completely decentralized, with over 10,000 discussion areas, called newsgroups.
WAN: (Wide Area Network) -- Any internet or network that covers an area larger than a single building or campus.
Web or WWW: (World Wide Web) -- Frequently used (incorrectly) when referring to "The Internet", WWW has two major meanings - First, loosely used: the whole constellation of resources that can be accessed using Gopher, FTP, HTTP, telnet, USENET, WAIS and some other tools. Second, the universe of hypertext servers (HTTP servers) which are the servers that allow text, graphics, sound files, etc. to be mixed together.