This document summarizes key aspects of the social media platform Twitter. It explains that Twitter allows users to follow others and engage with their tweets by favoriting or retweeting. It notes that Twitter has over 560 million registered users, most of whom are over 18 years old. The document also provides details on tweets, including that they are limited to 140 characters and can include text or photos. It briefly outlines Twitter's direct messaging feature and history, including that it was created in 2006 by Jack Dorsey and others originally as a podcasting app.