Instant messaging, sometimes abbreviated to IM, is a text-based means to communicate instantly over the internet and the local network. While some IM applications work with only one type of account, others, including Empathy, provide IM facilities by using accounts from different service providers. Some of these even support audio and video calling.

Some instant messaging applications can be used to connect to chat rooms, online places where like-minded people meet to talk. One popular means to connect to several chat rooms is the Internet Relay Chat, also known as IRC. IRC provides public chat rooms, which are open to anyone who creates an account on the IRC Server, and private chat rooms, which are password protected and open only to a select few.