This document provides an introduction to Twitter, including what Twitter is, how it has grown in popularity, examples of how different organizations and individuals use Twitter, basics of setting up a Twitter account and profile, Twitter terminology, how to integrate Twitter into other activities, and tools for enhancing one's Twitter experience. The key aspects covered are defining Twitter and its core functionality of microblogging, examples of how Twitter can be used personally, for business and news, basics of setting up an account and profile, common Twitter terminology, and ways of integrating Twitter into other online activities.