The streaming nature of the social media content, the increasing population of social media users, and the all-connected devices have significantly amplified the amounts of shared content. Navigating through these vast amounts of content and extracting meaningful information and knowledge has become an extremely interesting research topic in recent years. Many researchers have proposed algorithms and methods to organize the shared content into meaningful ways and thus enable efficient navigation through and exploration of the shared content. In this entry, we discuss the progress in three different but overlapping topics: detection of social trends, detection of events, and detection of influential users