This document provides an introduction and overview of Twitter. It discusses why people use Twitter and provides some examples of how Twitter has been used, including for reunions, saving businesses, political campaigns, and social movements. It then defines key Twitter terms and features such as tweets, mentions, replies, direct messages, retweets, favorites, hashtags, protected tweets, trending topics, and lists. It also addresses questions about how many Lebanese users are on Twitter and why people tweet. The document serves as a basic guide to understanding Twitter and its functions.