IRC = Internet Relay Chat.

Short for Internet Relay Chat, a multi-users chat system developed by Jarkko Oikarinen in Finland in the late 1980s. IRC has become very popular as more people get connected to the Internet because it enables people connected anywhere on the Internet to join in live discussions. Unlike older chat systems, IRC is not limited to just two participants.

To join an IRC discussion, you need an IRC client and Internet access. The IRC client is a program that runs on your computer and sends and receives messages to and from an IRC server. The IRC server, in turn, is responsible for making sure that all messages are broadcast to everyone participating in a discussion.

There can be many discussions going on at once; each one is assigned a unique channel. Each channel begins with a # and is dedicated to a different area of interest. 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.

IRC is considered one of the technologies of the Internet, along with FTP, Telnet, Gopher, and the Web. Because IRC requires special software and knowledge of technical commands, and because of its text-only environment, many people prefer to chat in GUI-friendly chat rooms found on the World Wide Web.