This document provides an overview and introduction to Twitter. It summarizes key facts about Twitter usage including that users create 600 tweets per second and nearly 50 million tweets per day. It then describes the typical Twitter user in terms of demographics like age, income, gender, and education. The document explains basic Twitter terminology such as following, followers, retweets, hashtags, and direct messages. It provides tips on using Twitter effectively and resources for learning more about Twitter analytics and best practices.