Twitter
Twitter is a real-time social network that connects everyone's ideas, opinions and news immediately. Twitter is a kind of online microblogging service that allow users to send and read text-based posts up to 140 characters. Twitter was created in March 2006 by Jack Dorsey and launched that at July 2006. In 2011, there are more than 300 million registered users. Everyday, there are more than 300 million tweets and handling over 1.6 billion search queries. Twitter has been described as the SMS / Text message of the internet.
Facebook
Facebook is a social networking service that launched in February 2004. In February 2012, Facebook has more than 845 million active users. Millions of people use Facebook everyday to keep up with friends, upload an unlimited number of photos, share links and videos, and learn more about the people they meet. User may join common-interest user groups, organized by workplace, sharing your location, showing out their own status, and instant messaging to all your friends. In addition, Facebook provide a small platform to all users that to play some apps like games and quiz to entertain their users. Facebook user can also share their video clips and photos to all of your friends.
LinkedIn is a business-rated social networking site. The site officially launched on May 2003. There are 4,500 members in the network at the end of the first month June 2003. In February 2012, LinkedIn becomes the world's largest professional network on the internet with more than 150 million members in more than 200 countries.