InterRecord Chat aka IRC

IRC is the original chatroom, a "virtual meeting place where people from all over the world can meet and talk". It's a totally separate protocol from the Web (aka HTTP).

If you say that Usenet is a Many to Many communication, which operates In Virtual Time / Virtual Space, then IRC is a Many To Many communications which operates in Real Time / Virtual Space. Both IRC and Instant Messaging offer Real Time / Virtual Space communications; though the latter started out as One - One, the two are converging somewhat.

IRC communications are limited to text, with some rich text ability but nothing standard. It requires a specialised agent, such as mIRC, which is installed on the computer, for full participation.

There are dozens of IRC networks, each containing multiple servers in various world wide locations, and having their own separate rules and regulations. You can sign in to any server with an available connection, and have access to the chat rooms on that network (but only the ones on that network).

Full participation in IRC gives you access to hundreds of chat rooms, aka channels. Each channel is started, and run, by anybody who connects to an IRC server and opens a channel with that name (assuming that name is not in use on that network). The channels can be moderated by the person starting a channel, or by the owners of a server on that network, or by anybody designated as a moderator by a current moderator.

Some IRC channels are connected to Java front end scripts. You can participate in limited fashion by accessing a web site which is running an IRC front end script. The Midnightz channel, on the Blitzed network, is an example of limited particpation; that script appears to be packaged in forums like Googolians, and many folks use this channel without realising what they are using.