The document discusses social networks and Twitter. It defines social networks as structures made of nodes that are generally individuals or organizations representing relationships. Twitter is defined as an online service that allows users to share 140-character updates. Twitter can be used for microblogging, quick answers, keeping up with news, and group collaboration. The document outlines how to use Twitter and create content through templates and widgets. It concludes that Twitter allows for quick information sharing across devices and learning to concisely communicate.