This document provides an introduction to Twitter, including what Twitter is, how to get started using it, terminology, examples of how different entities use Twitter, and tools to enhance the Twitter experience. It defines Twitter as a microblogging service that allows users to send short text updates of up to 140 characters. It recommends choosing a username, photo, and background and finding people to follow to build a network. Examples discussed include how companies like Zappos and CNN, celebrities like Shaq, and individuals use Twitter. It also outlines various Twitter clients and URL shorteners that can be used.