Twitter is a global platform for real-time expression and conversation where users can connect with people, information, ideas, viewpoints and news. Its services include real-time commenting, messaging and conversation. Twitter's applications offer social networking and micro-blogging services through mobile devices and the internet. It can also serve as a marketing tool for businesses, with its products and services including Twitter, Periscope, Promoted Tweets, Promoted Accounts, and Promoted Trends. Twitter was founded on March 21, 2006, by Jack Dorsey, Christopher Isaac Stone, Noah E. Glass, Jeremy LaTrasse, and Evan Williams, and is headquartered in San Francisco, California. On February 10, 2021, at 21:00 Beijing time, Twitter (TWTR.US) will hold its Q4 2021 earnings conference call online.