Twitter was founded in 2006 by Jack Dorsey, Evan Williams, and Biz Stone. It now has over 200 million users who send more than 150 million tweets daily. Tweets are limited to 140 characters, which has influenced microblogging. Twitter has changed how media and politics engage with society through real-time sharing of information. Key metrics for users and businesses include tweets, retweets, followers, and mentions. Twitter can be used personally to connect with others or by businesses to build their brand and get customer feedback. However, issues like privacy, misinformation, and addiction are concerns with both personal and business use. Advertising on Twitter allows targeting specific interests.