The following glossary defines 290 terms related to web hosting.  
Please do not reproduce without permission.
Use the form on the bottom of this page to submit new terms you'd like to see defined.

0 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

.com

A domain name used by commercial enterprises.

.gif

Graphics Interchange Format (GIF) filename extension

.jpg or .jpeg

Filename extensions of images in JPEG format.

.mov

File name extension for files with video sequences. A QuickTime player is needed in order to play such a file.

.mpg or .mpeg

Filename extension for files in MPEG format.

.zip

File name extension for files compressed with PKZIP program or similar.

100BaseT

Cabling used for FastEthernet.

10BaseT

Cabling used for Ethernet.

Active Channel

An Active Channel is a frequently updated information residing on a Web server. Users can subscribe to the channel if they have a CDF (Channel Definition Language) capable browser (e.g. Internet Explorer)

ActiveX

ActiveX is a brand name referring to a set of Microsoft's technologies and services based on COM (Component Object Model) widely released in 1997.  On the Internet, ActiveX can be used with IE versions 3 and above and with Netscape Navigator though plug-ins.  ActiveX control is a COM object, written as a DLL in a programming language like Visual Basic, that follows ActiveX standards.  Once downloaded, ActiveX controls have a large degree of freedom, presenting a security risk.  ActiveX controls have to be digitally signed by their creator.  Major competitor to ActiveX controls are JavaBeans.  Some hosts support ActiveX server components for ASP.

Address

Unique identifier of a web page. URL (Uniformed Resource Locator) is more frequently used for this purpose.

ADN

(Advanced Digital Network). A 56kbps dedicated communication line.

ADO

ActiveX Data Objects. Different data sources can be accessed in the same way within a single data model. The data can be located in various locations, like spreadsheets, databases or ordinary files.

ADSL

(Asymmetric Digital Subscriber Loop). High speed Internet access using the telephone line. It uses line-adaptive modulation and provides data speeds from 384kbps to 1.5 Mbps (upstream and downstream speeds are usually different). Unlike the dial up, it doesn't block the telephone line.

AIFF

Audio Interchange File Format. High quality audio file format introduced by Apple.

Anonymous FTP (Anon FTP)

A method for downloading and uploading files using FTP protocol without having a username or a password.  In place of a username, word "anonymous" is used, and in place of a password, email address is usually used.  If a hosting plan offers this service, your users will be able to download or upload files with FTP without having their own account.

Anonymous remailer

A SMTP server that allows sending anonymous email messages. It removes or changes the "From" field of all messages that it processes.

ANSI

American National Standards Institute. The U.S. standards organization.

Apache

Apache is an open-source (source code is freely available and can be shared) HTTP Web server software.  According to Netcraft survey, it is currently the most popular web server on the Net.  It is usually run on Unix operating system versions like Linux or BSD, but it can also be run on Windows.  It is a full-featured server with many powerful add-ons freely available.  Apache's major competitor is Microsoft's IIS.

Applet

Most often refers to a small Java program designed to run in a Web browser.  Java applets run in a sandbox, so they can't perform unauthorized functions like file reading or opening Net connections to other computer from your computer.

Archie

An online database of anonymous ftp sites and their contents. It allows to search the ftp repositories using file name queries.

Archive

Archives are large files containing valuable data. Archives are often compressed to save space.

Archive site

A server that contains archives. It can be accessed by FTP, E-mail or HTTP.

ARJ

One of the most popular compression formats.

ARPA

(Advanced Research Projects Agency) US governmental organization responsible for creating the ancestor of today's Internet.

ARPAnet

Network created by ARPA in 1969.

ASCII

(American Standard Code for Information Interchange). A standard for coding text files. Every character has an associated number and any text can be represented by a sequence of numbers.

ASP

Active Server Pages.  ASP is Microsoft's server-side scripting technology.  An Active Server Page has an .asp extension and it mixes HTML and scripting code that can be written in VBScript or JScript.  ASP is distributed with Microsoft's IIS web server, so most host using IIS will also offer ASP for dynamic web programming.  ASP.NET is the next version of ASP.  Other popular server-side scripting languages are Perl, PHP, ColdFusion, TCL, Python, and JSP.

Asynchronous Transfer Mode (ATM)

A set of network protocols designed for multimedia transmission. Data is partitioned into cells (53 bytes each) and passed along a virtual circuit. ATM allows for building very high speed networks.

Attachment

A part of an email message. Usually a file (a data file or a multimedia file) or a webpage. It is not a part of the text of the message, instead it is attached to the message.

AU

Audio file format for Unix systems.

Authentication

Authentication is used to confirm the identity of the other party involved in the data transmission.

AVI

Audio/Video Interleave. Audio file format used by Microsoft Widows.

B Channel

Bearer Channel. It is a 64 Kbps communication channel in ISDN.

Backbone

Main high-speed network connection composing the Internet.  Backbones are operated by major telecommunications companies like Sprint, MCI, or AT&T.  Internet backbone maps are here.  

Bandwidth

Bandwidth is the amount of data that can be transferred over the network in a fixed amount of time.  On the Net, it is usually expressed in bits per second (bps) or in higher units like Mbps (millions of bits per second).  28.8 modem can deliver 28,800 bps, a T1 line is about 1.5 Mbps.

Basic Rate Interface (BRI)

A BRI line is one of two access methods for ISDN (the other one is Primary Rate Interface - PRI). A BRI has two 64 Kbps B channels and one 16 Kbps D channel.

Baud

The rate at which bits are transmitted over a communication link. Baud is the number of transitions (that are used to encode bits) that take place in one second.

Binary

Data represented in binary format uses only two digits - 0 and 1.

binary mode

FTP client mode used to transfer binary files (multimedia files, executables and other data files). Not suitable for transferring normal text files.

Bit

(Binary DigIT) the smallest unit of information, comprising of either a 1 or 0.

Bit rate

The speed at which bits are transmitted over a communication link. Expressed in bits per second (bps).

Body

The part of an email message that contains the actual text of the message.

Bookmark

A way of storing a frequently visited website address. It is then easier to access the website in the future.

Bot

An automated piece of software that can be used in chat rooms or to crawl the web.

BRB

Be Right Back

Bridge

A network device used to connect two LANs using different cabling.

Broadcast

Sending a packet to all machines on the network.

Browser

Computer program that allows to search the World Wide Web and displays the content of the webpages. Examples are Mosaic, Netscape, Mozilla, Opera and Internet Explorer.

Browser sniffing

The process in which the web site tries to determine what kind of web browser the user is using. This is done to suit the website to the particular capabilities of the browser.

BTW

By The Way

C/C++

Popular programming languages (C++ includes objects) that can be used to create server programs that run after compilation.  C and C++ were not designed specifically for web programming, but they can still be useful, especially because mature compilers producing very fast code and large code libraries already exist.

Cable Modem

A cable modem is used for connecting to the Internet using the cable TV infrastructure. It offers high speed Internet access.

Cascading Style Sheets (CSS)

A style-sheet determines how the HTML document is displayed by the browser. The current version of CSS is version 2 (CSS2).

CCIT

Comite Consultatif International Telegraphique et Telephonique (International Telegraph and Telephone Consultative Committee). International telecommunication standards body.

CERN

(Conseil Europeen pour la Recherche Nucleaire) A nuclear research laboratory where the World Wide Web was invented.

Certificate

Digital ID used for SSL transactions.  It includes owner's public key, the name of the owner, the issuer, hostname, and the expiration date.

Certificate Authority

A company trusted by a browser maker that issues digital certificates that are supposed to guarantee that the company is what it claims to be for use in encrypted digital transactions though SSL.  Verisign is the biggest certificate authority.

CGI

Common Gateway Interface.  A standard for interfacing web servers with an executable application.  A CGI program can be written in any language like Perl or C/C++ and it is often stored in a special directory like /cgi-bin.  CGI is often used to process data from HTML forms.

cgi-bin

A directory on the server where the executable CGI scripts reside.

Channel Definition Format (CDF)

A way of defining the server-push channels for accessing frequently changing web content.

CHAP

(Challenge Handshake Authentication Protocol). An authentication protocol used in PPP protocol. Uses a username and a password.

Client

A computer program that requests a service from the server program, usually over the network.

Client/Server

A network architecture where a system is divided into two parts: the client and the server.

clustering

Connecting many computers and making them appear as one machine. This is done to increase reliability and performance.

Co-location (colo)

Putting a web server in a dedicated facility that provides high-speed Internet connection, security, environment, backup power, and technical support.  Unlike the dedicated server, the client controls both hardware and software.  

Cobalt RaQ

Server appliance made by Cobalt specifically for hosting companies.  Newest RaQs are Linux-based and provide an easy-to-use interface.  RaQs have no features that can't be had in a regular Linux box but they offer pre-installed programs and Cobalt's support. Here is the discussion forum for RaQs.

ColdFusion

ColdFusion is an easy to use server-side scripting language developed by Allaire.  It comes with ColdFusion Studio, a visual IDE.  Here is Allaire's ColdFusion page.  Other popular server-side scripting languages are ASP. Perl, PHP, TCL, Python, and JSP.

command-line interface

The opposite of the GUI (Graphical User Interface). A way of interacting with a computer system using the keyboard and a text-only display. Usually more powerful, but less user-friendly thatn a GUI.

Control Panel

Control panel included in web hosting packages is an online web-based application that allows you to easily manage different aspects of your account.  Most control panels will let you upload files, add email accounts, change contact information, set up shopping carts or databases, view usage statistics, etc.  

Cookie

A Cookie is a piece of data that is saved in the user's browser by the web server. It is used to customize user's browsing experience.

CPU

Central Processing Unit. The most important part of the computer.

Crawler

Also known as spider, an automated software that retrieves webpages and follows the hyperlinks contained in them. Used to generate indexes used by search engines.

D Channel

The ISDN signaling channel. Runs at 16 or 64 Kbps.

Data transfer

In Web hosting, the total size of files transferred by an account in a month.  Sites with a lots of graphics, downloads, or streaming audio or video and a lot of visitors will require plans with more available transfer.

Database

Data in a structured format stored on a web server.  Most popular type is a relational database.  The most common query (information retrieval) language for relational databases is SQL.  Linux-based hosts most commonly include MySQL database and Windows NT-based hosts usually include Access or MS SQL databases.

Dedicated Server

Similar to co-location, except that you lease or rent hardware from a Web host.  The main advantage over co-location is easier upgrade and usually better support.  Getting a dedicated server or co-locating is necessary for sites that outgrow shared servers because they use a lot of bandwidth and resources or they require total control over software environment.  

DES

Data Encryption Standard - an U.S. government approved cipher. It is easy to break in its simplest form, but used multiple times with key of at least 128 bits provides good security.

DHCP

(Dynamic Host Configuration Protocol). An automated way of obtaining an IP address in the Local Area Network.

Dial up

Dialup access is a way of connecting a computer to the Internet using a modem and the telephone line. It is rather slow and blocks the telephone line.

DNS

Domain Name System.  Internet service that maps Internet domains into corresponding IP addresses.  DNS database is distributed and replicated among many DNS servers, so when you change your domain's IP address, the changes take a while to propagate.

Domain name

Domain name is an easy-to-remember address that can be translated by DNS into server's IP address.  Domain names are hierarchical.  Domain's suffix indicates which TLD (top level domain) it belongs to, for example .com, .gov, .org, .net, or .jp.  Recently ICANN (Internet Corporation for Assigned Names and Numbers) added several new TLDs, like .biz, .pro., and .museum.

DSL

Digital Subscriber Line. A better way of connecting a computer to the Internet using the telephone line. It's faster than the dialup and doesn't block the telephone line. However, it is more expensive because the special equipment is required.

E-Business

Using web and Internet technologies in conducting the business activities. Also expanding end enhancing traditional business practices by means of the Internet.

EIA

(Electronic Industries Association). An industry trade organization involved with definition of standards for electrical consumer products. It works jointly with the TIA (Telecommunications Industry Association).

Electronic Mail (E-Mail, email)

One of the most popular Internet services. Basically it's the transmission of text based messages. An email message can also contain more structured elements, like tables, images and multimedia. It can also be used to send various data files, by means of attachments. You have to have an email account in order to be able to use this service.

Encryption

Encryption means encoding data using a cryptographic cipher. Encrypted data can be read (decrypted) only by an authorized entity.

Ethernet

Local Area Network (LAN) protocol invented by Xerox Corporation. It is a broadcast protocol that uses CSMA/CD method and utilizes electrical cables. It can run at various speeds: 10Mbps, 100Mbps and even 1000Mbps. IEEE 802.3 standard describes Ethernet. Word Ethernet is also sometimes used to describe the implementation that runs at the speed of 10Mbps.

Extranet

A part of the company's network that is made accessible for some group of people. Sometimes protected by a password or some other kind of authentication. It allows users to access some of the non-public data, eg. a person's credit card balance.

FAQ

(Frequently Asked Question) Lists of frequently asked questions and answers to them are used as a way of sharing knowledge on the web. They are a very good way of finding solutions to different problems. Some companies include them in their websites to minimize the number of Customer Support inquiries.

Fast Ethernet

Fast Ethernet is the implementation of Ethernet standard that operates at the speed of 100Mbps.

FCC

(Federal Communications Commission). U.S.A. telecommunications regulatory organization. It controls standards that pertain to electronic and electromagnetic transmission and also licenses the frequencies and bandwidth for the commercial use.

FDDI

(Fiber Distributed Data Interface). A very high speed network protocol. Uses fiber-optic cable, and is mainly used as the backbone network protocol due to its speed. It is also often the choice for critical applications due to its reliability.

Fibre Optic Cable

A cable used for transmitting data as a light wave. A fiber optic cable is composed of one or more optical fibers. It is more expensive that copper wire, but offers higher transmission speeds and allows for communication over larger distances.

Filename extension

Last three or four letters of a file name that appear after the dot. Used to designate the type of file and the format used.

Filtering

Screening network packets for certain properties, such as the source or destination address, protocol used or even a pattern in the data. It is used in firewalls in order to decide if the traffic is to be forwarded or rejected. Provides the basis for network security.

Finger

A Unix program used to display information about users of the system. Can be used remotely.

Firewall

Firewall refers to either software-only or separate software and hardware combination that serves to protect an internal network or a computer from attacks and unauthorized access by sitting between the Internet and the internal network. 

Flame

An insulting email message sent to an individual as punishment for not adhering to the netiquette. Can be sometimes seen in the newsgroups or on internet message boards.

FPU

Floating Point Unit. A part of the computer responsible for high precision mathematical operations.

Frame Relay

A fast packet switching protocol. Used mainly in Wide Area Networks. It differs from ATM in that packets can have variable length.

FrontPage Extensions

Microsoft's server-side applications that lets users of FrontPage Web site creation tool to incorporate "web-bots" that perform pre-packaged function like full-text Web site searching or adding a hit counter.  FrontPage extensions are also available for Unix-based operating systems but some hosts refuse to use them because of potential security holes.

FTP

File Transfer Protocol.  The Internet protocol defining how to download and upload files between a client and an FTP server.  Popular client FTP programs are CuteFTP and WS_FTP.  Major browser also have FTP capability.

FTPmail

Using email messages to access the FTP sites. Requires a special software installed on the server.

FYI

For Your Information

Gateway

A network device used to translate between two different protocols. Used to interconnect two networks that use incompatible protocols.

GIF

(Graphics Interchange Format) A graphic file format invented by Compuserve. One of the most widely used formats for internet and web. Uses a lossless compression method, thus ensuring that the quality of the image is not lowered.

Gigabit Ethernet

Gigabit Ethernet is the Ethernet standard implementation that runs at 1000Mbps.

Gigabyte (Gb)

1024 Megabytes.

Graphical User Interface (GUI)

A way of interacting with the computer that relies on graphical symbols. Most often requires a mouse. It is less powerful then the command-line interface, but is more user friendly and is easier to learn for users without technical background.

Hexadecimal color-notation system

A way of defining colors. Uses RGB scheme and associates a two digit hexadecimal number with each base color (red, green and blue).

Hit

In the WWW world "hit" is used to describe a single request made by a web browser. The data transmitted by the web server in response to the request is a text file or a binary file (images, audio, video, executables and other data).

Home Page

Main web page owned by a company, organization or an individual. This is the page that is initially displayed when user makes a request for a particular domain name.

Host

A networked computer dedicated to providing a certain kind of service. Usually refers to a computer that stores the website files and has a web server running on it.

HTML

(Hypertext Markup Language). It is the language in which web pages are written. It allows the images to be combined with text and offers wide range of formatting capabilities. One of the most important features of HTML is hypertext, that allows web pages to be liked one to each other. HTML relies on tags, which have the following form: