Facebook is an American for-profit corporation and online social media and social networking service based in Menlo Park, California, United States. The Facebook website was launched on February 4, 2004, by Mark Zuckerberg, along with fellow Harvard College students and roommates, Eduardo Saverin, Andrew McCollum, Dustin Moskovitz, and Chris Hughes.
Twitter is an online news and social networking service where users post and read short 140-character messages called "tweets". Registered users can post and read tweets, but those who are unregistered can only read them. Users access Twitter through the website interface, SMS or mobile device app. Twitter Inc. is based in San Francisco and has more than 25 offices around the world.