Internet Dictionary
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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.
Apache - The most common web server (or HTTP server) software on the Internet. Apache is an open-source application originally created from a series of changes (”patches”) made to a web server written at the National Center for Supercomputing Applications, the same place the Mosaic web browser was created.
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.
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 (bps.) 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” 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).
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 were very small, running on a single IBM clone PC with 1 or 2 phone lines. Some were 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.
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.
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.
CSS - (Cascading Style Sheet) A standard for specifying the appearance of text and other elements. CSS was developed for use with HTML in Web pages but is also used in other situations, notably in applications built using XPFE. CSS is typically used to provide a single “library” of styles that are used over and over throughout a large number of related documents, as in a web site. A CSS file might specify that all numbered lists are to appear in italics. By changing that single specification the look of a large number of documents can be easily changed.
DHTML - (Dynamic HyperText Markup Language) DHTML refers to web pages that use a combination of HTML, JavaScript, and CSS to create features such as letting the user drag items around on the web page, some simple kinds of animation, and many more.
DNS - (Domain Name System) The Domain Name System is the system that translates Internet domain names into IP numbers. A “DNS Server” is a server that performs this kind of translation.
Email - (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.
FAQ - (Frequently Asked Questions) FAQs are documents that list and answerthe most common questions on a particular subject. There are hundreds of FAQs on subjects as diverse as Pet Grooming and Cryptography. FAQs are usually written by people who have tired of answering the same question over and over.
Gateway - The technical meaning is a hardware or software set-up that translates between two dissimilar protocols, for example America Online has a gateway that translates between its internal, proprietary e-mail format and Internet e-mail format. Another, sloppier meaning of gateway is to describe any mechanism for providing access to another system, e.g. AOL might be called a gateway to the Internet.
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.
IMAP - (Internet Message Access Protocol) IMAP is gradually replacing POP as the main protocol used by email clients in communicating with email servers.
Using IMAP an email client program can not only retrieve email but can also manipulate message stored on the server, without having to actually retrieve the messages. So messages can be deleted, have their status changed, multiple mail boxes can be managed, etc.
Java - Java is a network-friendly programming language invented by Sun Microsystems. Java is often used to build large, complex systems that involve several different computers interacting across networks, for example transaction processing systems. Java is also used to create software with graphical user interfaces such as editors, audio players, web browsers, etc. Java is also popular for creating programs that run in small electronic devicws, such as mobile telephones. Using small Java programs (called “Applets“), Web pages can include functions such as animations,calculators, and other fancy tricks.
Kilobyte - A thousand bytes. Actually, usually 1024 (210) bytes.
LAN - (Local Area Network) A computer network limited to the immediate area, usually the same building or floor of a building.
Mail 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.
Netiquette - The etiquette on the Internet.
Open Content - Copyrighted information (such as this Glossary) that is made available by the copyright owner to the general public under license terms that allow reuse of the material, often with the requirement (as with this Glossary) that the re-user grant the public the same rights to the modified version that the re-user received from the copyright owner. Information that is in the Public Domain might also be considered a form of Open Content.
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 along different routes by special machines along the way. This way many people can use the same lines at the same time. You might think of several caravans of trucks all using the same road system to carry materials.
RDF - (Resource Definition Framework) A set of rules (a sort of language) for creating descriptions of information, especially information available on the World Wide Web. RDF could be used to describe a collection of books, or artists, or a collection of web pages as in the RSS data format which uses RDF to create machine-readable summaries of web sites. RDF is also used in XPFE applications to define the relationships between different collections of elements, for example RDF could be used to define the relationship between the data in a database and the way that data is displayed to a user.
SDSL - (Symmetric Digital Subscriber Line) A version of DSL where the upload speeds and download speeds are the same.
Tag - The term “tag” can be used as a noun or verb. As a noun, a tag is a basic element of the languages used to create web pages (HTML) and similar languages such as XML. Another, more recent meaning of tag is related to reader-crearted tags where blogs and other content (such as photos, music, etc.) may be “tagged” which means to assign a keyword, such as “politics” or “gardening”, this enables searches for “all the blog postings in the past week that are tagged ‘prenatal care’”
TLD - (Top Level Domain) The last (right-hand) part of a complete Domain Name. For example in the domain name www.matisse.net “.net” is the Top Level Domain. There are a large number of TLD’s, for example .biz, .com, .edu, .gov, .info, .int, .mil, .net, .org, and a collection of two-letter TLD’s corresponding to the standard two-letter country codes, for example, .us, .ca, .jp, etc.
Upload - Transferring data (usually a file) from a the computer you are using to another computer. The opposite of download.
URL - (Uniform Resource Locator) The term URL is basically synonymous with URI. URI has replaced URL in technical specifications.
Virus - A chunk of computer programming code that makes copies of itself without any concious human intervention. Some viruses do more than simply replicate themselves, they might display messages, install other software or files, delete software of files, etc. A virus requires the presence of some other program to replicate itself. Typically viruses spread by attaching themselves to programs and in some cases files, for example the file formats for Microsoft word processor and spreadsheet programs allow the inclusion of programs called “macros” which can in some cases be a breeding ground for viruses.
WAIS - (Wide Area Information Servers) Developed in the early 1990s WAIS was the first truly large-scale system to allow the indexing of huge quantities of information on the Web, and to make those indices searchable across networks such as the Internet. WAIS was also pioneering in its use of ranked (scored) results where the software tries to determine how relevant each result it.
Webpage - A document designed for viewing in a web browser. Typically written in HTML. A web site is made of one or more web pages.
WWW - (World Wide Web) World Wide Web (or simply Web for short) is a term 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), more commonly called “web servers”, which are the servers that serve web pages to web browsers.
XHTML - (eXtensible HyperText Markup Language) Basically HTML expressed as valid XML. XHTML is intended to be used in the same places you would use HTML (creating web pages) but is much more strictly defined, which makes it a lot easier to create sofware that can read it, edit it, check it for errors, etc. XHTML is expected to eventually replace HTML.
XML - (eXtensible Markup Language) A widely used system for defining data formats. XML provides a very rich system to define complex documents and data structures such as invoices, molecular data, news feeds, glossaries, inventory descriptions, real estate properties, etc. As long as a programmer has the XML definition for a collection of data (often called a “schema”) then they can create a program to reliably process any data formatted according to those rules. XML is a subset of the older SGML specification - the definition of XML is SGML minus a couple of dozen items.
