Internet Relay Chat (IRC) is a form of instant communication over the Internet. It is mainly designed for group (many-to-many) communication in discussion forums called channels, but also allows one-to-one communication.
Contrary to most Instant Messenger (IM) systems, users usually don't connect to a central server. Instead, users connect to a random server in a network, and servers relay messages from one to the next.
Here's a typical example:
When you connect to the Freenode network
http://freenode.net/), you point your IRC client at the
irc.freenode.net. That server will redirect your client
to a random server on the network, such as
Once you're connected, you can send messages to all other users
connected to the same network, and you can join all channels on the same
network. You might join the
#emacs and the
channels, for example. (Typically, channel names begin with a hash
Once you have joined a channel, anything you type will be broadcast to all the other users on the same channel.
If you want to address someone specifically, for example as an answer to a question, it is customary to prefix the message with the nick followed by a colon, like this:
deego: fsbot rules!
Since this is so common, you can use <TAB> to do nick completion.