Twitter is an online social networking service that enables users to send and read short 140-character messages called "tweets".
email
Annotations:
Electronic mail, most commonly referred to as email or e-mail since c 1993,[2] is a method of exchanging digital messages from an author to one or more recipients
face book
Annotations:
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.[7]
instgram
Annotations:
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
Annotations:
YouTube is a video-sharing website headquartered in San Bruno, California. The service was created by three former PayPal employees in February 2005.