Gateway
The technical meaning is a hardware or software configuration that translates between two (or more) different protocols. For example AOL used to use a proprietary email program which used a Gateway to allow it to connect with other email programs using the more common POP3 protocol. AOL has since changed to a more standard email protocol (luckily).

GIF -- (Graphic Interchange Format)
A common format for image files, especially suitable for images containing large areas of the same color. GIF format is good for graphical images which do not contain complex color variations and is more suitable for Web graphics. GIF format is a poor choice for digital photographs because of the huge number of color variations within the photographs. Almost all animations on the Web are GIFs.

Gigabyte
Normally 1024 Megabytes. However some use Gigabyte to mean 1000 Megabytes as well.

Hit
A "Hit" on a web site is every time the page is loaded and every time every graphic or media file in that page is loaded from a single request (view). Lots of times you'll hear someone bragging that their site got a "million hits". But, hits are not as important as "unique" visitors. If you have a web page with 160 graphics on it and one midi file, each time that page is requested (viewed) it would generate 162 hits (one for each graphic, one for the midi file and one for the page itself. And every time the page was reloaded or refreshed it would generate another 162 hits and so on. Unique visitors are the real measure of a Web page's popularity since it counts only the "unique" visitor (by IP address) who has visited that page.

Home Page
Home Page has several meanings. It can mean the page your browser opens with when you open your browser (like our Start Page). It can mean the "home page" of a Web site. For instance our Web site's home page is http://funonboone.com.

Host
A "Host Machine" provides a service to other computer. A Host Machine usually provides  several services, such as SMTP (email) and HTTP (web) and FTP (File Transfer Protocol).

HTML -- (HyperText Markup Language)
The language of Web Sites. This is the code that creates Web pages. Just about every page on the Web is written in HTML or similar related language. "Hyper" in the term "Hypertext" simply means you can create links to other pages from a block of text or an image. These are called "Hyperlinks".

HTTP -- (HyperText Transfer Protocol)
The main protocol for accessing Web pages across the Internet. Requires a HTTP client (browser) on one end and a HTTP server (Web server) on the other (DUH!). HTTP is the reigning king of protocol used on the World Wide Web (WWW).

IMAP -- (Internet Message Access Protocol)
IMAP has been trying to replace  POP3 (Post Office Protocol 3) as the main protocol used by email clients in communicating with email servers for the last five years. So far, it hasn't had a great deal of success, but probably will, eventually replace POP3. Why? Because it gives the user so much more control of Email sitting on the Mail Server. Using IMAP an email  program can not only retrieve email but can also manipulate messages stored on the mail server, without actually having to download the messages. You can manage multiple mailboxes right on the Web server, organize your email, delete email, and so forth without having to download it to your email program.

IMHO -- (In My Humble Opinion) or (In My Honest Opinion)
An Internet Chat/Forum shorthand term. Normally you use this when you're saying something controversial or disagreeing with someone. But, you can use it however you want. We don't care :)

Internet (The)
An extremely immense collection of inter-connected networks that are connected using the TCP/IP protocols and that evolved from the ARPANET of the late 60's and early 70's.The Internet connects tens of thousands of independent networks into a vast global internet and is the largest Wide Area Network in the world. It is estimated that there are currently over 15 billion Web sites on the World Wide Web. Did you build yours yet?

Intranet
A LAN (local Area Network) or a private network not accessible by the public. For example an company Intranet used for moving mail and information from one department to another. Accessible from the company's network but not to the public.

IP Address
Every machine that is on the Internet (yes yours too!) has a unique IP number - if a machine does not have an IP number, it is not really on the Internet. IP Addresses are unique and can be traced to you. It is not easy to disguise or conceal your IP address. Really, it's not :)

IRC -- (Internet Relay Chat)
The first "Internet Chat". IRC is 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 chats or one-on-one private chats. IRC still has many users, but has been largely replaced chat programs like MSN, Yahoo, etc. To access IRC you need a chat client like MIRC or pIRCh. Wow, it's been a long time since I've seen those names.

ISDN -- (Integrated Services Digital Network)
Basically a way to move more data over existing regular phone lines. ISDN is 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 56,000or 64,000 bits-per-second. Unlike DSL, ISDN can be used to connect to many different locations, one at a time, just like a regular telephone call, as long the other location also has ISDN. ISDN never gained much popularity because it is expensive and compare to today's broadband, is relatively slow. It is very rarely seen these days.

ISP -- (Internet Service Provider)
A company or organization that provides access to the Internet usually for profit. MSN, AOL, SBC/Yahoo, Comcast, Road Runner, etc. are National ISPs. You probably have one or local ISP's struggling to survive in your town too. 

IT -- (Information Technology)
A general term that refers to the entire field of Information Technology. This can be anything from computer hardware to programming to network management to software implementation on a network. Most medium and large size companies have IT Department.

Java
Java is a network-friendly programming language invented by Sun Microsystems. The advantage to Java is that it's cross-platform. That means it can run on Windows, Linux, Unix, etc.  Java can be used to create software with graphical user interfaces such as editors, audio players, web browsers, etc. As well as create special-effects on Web sites (like snow falling, rain showers, melting images, fire, etc. Java is also popular for creating programs that run in small computerized devices like cell phones..

JavaScript
JavaScript is a programming language that is mostly used in web pages, usually to add features that make the web page more interactive. When JavaScript is included in an HTML file it relies upon the browser to interpret or "run" the JavaScript.

JPEG -- (Joint Photographic Experts Group)
JPEG is most commonly mentioned as a format for image files. JPEG format is a better choice image format for photographs, digital photography, or other detailed graphics with many colors and shades of color. JPEG is the second most common form of graphic on the Web next to GIF.

Kilobyte
1024 bytes (correct) also 1000 bytes (incorrect)