Twitter (twitter.com) is social networking and micro-blogging site that allows users to post their latest updates. An update is limited by 140 characters and can be posted through three methods: web form, text message, or instant message.
Twitter was founded in 2006 by Evan Williams and Biz Stone (formerly of Google)
Twitter allows users to post text updates via SMS, instant messaging, email, Twitter’s website and third party applications. Users have their own profile page that displays their latest updates. In addition, users can become “friends” with one another, or simply be a “follower.” Other than reading another person’s profile page, a user can also receive others’ updates through text messages, RSS or third party applications.