Twitter is an online social networking service that enables users to send and read short 140-character messages called "tweets".
Electronic mail, most commonly referred to as email or e-mail since c 1993, is a method of exchanging digital messages from an author to one or more recipients
3 face book
is an online social networking service headquartered in Menlo Park, California. Its website was launched on February 4, 2004, by Mark Zuckerberg with his college roommates and fellow Harvard University students Eduardo Saverin, Andrew McCollum, Dustin Moskovitz and Chris Hughes.
is an online mobile photo-sharing, video-sharing and social networking service that enables its users to take pictures and videos, and share them on a variety of social networking platforms, such as Facebook, Twitter,Tumblr and Flickr.
5 you tube
YouTube is a video-sharing website headquartered in San Bruno, California. The service was created by three former PayPal employees in February 2005.