X, formerly known as Twitter, is an online social media and social networking service operated by the American company X Corp., which succeeded Twitter, Inc.
Twitter is an American microblogging and social networking service where users post and interact with messages called "tweets". Registered users can post, like, and retweet tweets, while unregistered users can only read them. Users access Twitter through its website interface, Short Message Service (SMS), or its mobile-device application software ("app"). Twitter, Inc. is headquartered in San Francisco, California, and has over 25 offices globally. Initially, tweets were limited to 140 characters but were expanded to 280 for non-CJK languages in November 2017. Audio and video tweets are typically limited to 140 seconds for most accounts.
Twitter was founded by Jack Dorsey, Noah Glass, Biz Stone, and Evan Williams in March 2006 and launched in July of the same year. By 2012, it had over 100 million users posting 340 million tweets daily, with the service handling an average of 1.6 billion search queries per day. In 2013, it was among the ten most-visited websites and has been likened to "the SMS of the Internet". As of 2018, Twitter boasted more than 321 million monthly active users.