Instant Messaging
From MissionTechWiki
Instant messaging, or IM is a useful tool for text-based communication that is more "Real-Time" than e-mail. Instant messaging is more analogous to a conversation whereas typical e-mail is correspondence. There are several dominant chat networks, and any number of clients that can be used on those networks. Each has various benefits and detractors, but the most important facet of any IM service is the people on that service.