Internet relay chat (IRC),
Definition of Internet relay chat (IRC):
Facility provided by a software such as ICQ or some websites in chat rooms. The internet users can have live conversations with those present in the chat room (or otherwise online on the Internet) by sending and receiving emails instantly over the Internet.
A system allowing two or more users to send text messages to one another in real time; (also) the notional space in which such messaging takes place; abbreviated IRC.
Meaning of Internet relay chat (IRC) & Internet relay chat (IRC) Definition