IANA (Internet Assigned Numbers Authority)

The central registry for various Internet protocol parameters, such as port, protocol and enterprise numbers, and options, codes and types. The currently assigned values are listed in the Assigned Numbers document.

I-beam cursor

A flashing cursor shaped like a capital I used to indicate that you can edit text on screen. If you use a Windows word processor, the mouse pointer turns into an I-beam cursor when you move it over the main page and returns to an arrow shape when you move it over the menu bar or other controls.

IBM Compatible Computers

Computers that use the same software as the computers introduced by the IBM Corporation in the early 80's. These computers are manufactured by many companies and are sometimes referred to as "clones".


A small picture displayed on screen to identify a command or file. Many word processors use an icon of a magnifying glass on a button to indicate that it will start a search function. In Windows, each application you install has its own icon and its data files often use the same icon.

Image editor

Software that lets you edit, change or paint new parts of an image. Professional designers might use an image editor to remove any blemishes from a photograph. Windows has its own basic image editor called Paint, stored in the Accessories folder.


The function in an application that allows you to use a data file produced by another program and stored in another format. For example, if you use Microsoft Word and want to read a document written with WordPerfect, you will need to choose the import menu option in Word and tell Word that it should convert the WordPerfect codes to native Word codes and formats. The opposite is called Export.


An "index" is a list of the messages contained in a conference or a mail folder. Indexes generally show the date of the message, its title (or subject), the name of the user who wrote it, and an indication (with a "*" marker) of whether you have read that message.


To transfer information into a computer. If you type text on your keyboard you are inputting data into the computer. Other examples are using a scanner or using a mouse to draw on screen.

INS key

A special key on a PC that switches the typing mode between insert and overwrite. If you are in overwrite mode, any existing characters will be overwritten with the new text you type in. If you are in insert mode, any existing characters are moved along automatically to make space for the new characters. Most word processors tell you which mode you are in by displaying OVR for overwrite and INS for insert in the status bar at the bottom of the screen .


The steps involved in copying and setting up an application program on your hard disk. The steps include copying the files from the floppy disks or CD-ROM (on which the application is sold) on to your hard disk, then configuring the options for your requirements.


A multimedia title that allows the user to control progress through the book. Instead of the software showing page one, then two and so on, the user can move around and click on hypertext links and hotspots that move him around the book in a random order .


(See GUI)


An international network that links thousands of computers using telephone and cable links. Users connect to server computers, which are rather like a local phone exchange: you use a modem to connect to the server from home and so access the entire network. You can send email over the Internet and transfer files and text from a PC in London to another in New York, all for the price of a local phone call. To get on to the Internet, you'll need a modem and an account with a server, normally called a service provider.

Internet Protocol (IP)

An industry standard, connectionless, best-effort packet switching protocol used as the network layer in the TCP/IP Protocol Suite.

Internet Society (ISOC)

A non-profit, professional organization that supports the technical evolution of the Internet and stimulates the interest of members of the scientific and academic communities, industry, and the public regarding technology and the applications of the Internet. The ISOC also promotes the development of new applications for the Internet by publishing a quarterly newsletter, the Internet Society News, and by and holding an annual conference, called INET.


Meaning Internet information Center, InterNIC is the combined name for the providers of registration, information, and database services to the Internet. InterNIC is who you contact if you want to register a domain name on the Internet.

IP Address (Internet Protocol Address)

The 32-bit address defined by the Internet Protocol. Every resource on the Internet has a unique numerical IP address, represented in dotted decimal notation. IP addresses are the closest thing the Internet has to phone numbers. When you "call" that number (using any number of connection methods such as FTP, HTTP, Gopher, etc.) you get connected to the computer to which that IP address is assigned.


The world-wide party line of the '90s. IRC allows multiple users to converse in real time on different channels. Channels (which have a # sign preceding their name) vary in traffic and content. Channel operators (or Ops) moderate the conversation, and have the ability to "kick" people from channels, or even ban them if their actions warrant it. IRC clients are available for nearly all platforms.

ISDN (Integrated Services Digital Network)

A relatively new technology which combines voice and digital network services in a single medium. ISDN makes it possible for communications carriers to offer their customers digital data services as well as voice connections through a single line. CCITT defines the standards relating to ISDN.

ISP (Internet Service Provider)

An ISP is a company that maintains a network that is linked to the Internet via a dedicated communication line, usually a high-speed link known as a T1. An ISP offers use of its dedicated communication lines to companies or individuals (like me) who can't afford $1,300 a month for a direct connection. Using a modem, you can dial up to a service provider whose computers will connect you to the Internet, typically for a fee.