JargonFile/entries/channel.txt

channel

n. [IRC] The basic unit of discussion on IRC. Once one joins a channel,
everything one types is read by others on that channel. Channels are named
with strings that begin with a # sign and can have topic descriptions (which
are generally irrelevant to the actual subject of discussion). Some notable
channels are #initgame , #hottub , callahans , and #report. At times of
international crisis, #report has hundreds of members, some of whom take
turns listening to various news services and typing in summaries of the
news, or in some cases, giving first-hand accounts of the action (e.g., Scud
missile attacks in Tel Aviv during the Gulf War in 1991).