Twitter is a service for friends, family, and co–workers to communicate and stay connected through the exchange of quick, frequent messages.  People write short updates, often called “tweets” of 140 characters or fewer.  These messages are posted to your profile or your blog, sent to your followers, and are searchable on Twitter search.

Go now to: Twitter: What are you doing?

Instant Messaging (IM) is a form of real-time communication between two or more people based on typed text. The text is conveyed via computers connected over a network such as the Internet.

Instant messaging (IM) and chat are technologies that create the possibility of real-time text-based communication between two or more participants over the internet or some form of internal network/ intranet.