Twitter is an online news and social networking service where users post and interact with messages, "tweets", restricted to 140 characters. Registered users can post tweets, but those who are unregistered can only read them. Users access Twitter through its website interface, SMS or a mobile device app. Twitter Inc. is based in San Francisco, California, United States, and has more than 25 offices around the world.
Twitter was created in March 2006 by Jack Dorsey, Noah Glass, Biz Stone, and Evan Williams.
The first Twitter prototype, developed by Dorsey and contractor Florian Weber, was used as an internal service for Odeo employees and the full version was introduced publicly on July 15, 2006.
The service rapidly gained worldwide popularity. In 2012, more than 100 million users posted 340 million tweets a day, and the service handled an average of 1.6 billion search queries per day. In 2013, it was one of the ten most-visited websites and has been described as "the SMS of the Internet". As of 2016, Twitter had more than 319 million monthly active users. On the day of the 2016 U.S. presidential election, Twitter proved to be the largest source of breaking news, with 40 million election-related tweets sent by 10 p.m. (Eastern Time) that day.