Facebook is a social networking service and website launched in February 2004 that is operated and owned by Facebook, Inc.. 

Users can create a personal profile, add other users as friends and exchange messages, including automatic notifications when they update their profile.Additionally, users can join a user group that has a specific purpose, sorted by workplace, school, college, or other characteristics.

Twitter is a website owned and operated by Twitter Inc.., Which offers a social networking micro-blogging that allows users to send and read messages called Chirp (tweets). Tweets are text posts of up to 140 characters displayed on the user profile page. Tweets can be seen outside, but senders can restrict message delivery to their friends list only. Users can see other writers chirp known as followers (Follower).

LinkedIn is a social networking website oriented businesses, mainly used for professional networking. As of September 2007 this site has over 14 million registered users, covering 150 industries and more than 400 economic areas are classified according to merit. 

LinkedIn CEO Dan Nye is currently and offices are located in Mountain View, California. The company is funded by Greylock, Sequoia Capital, Bessemer Venture Partners and European Founders Fund. LinkedIn began to reap the benefits (positive cash flow) since March 2006.

MySpace is a social networking site. Its headquarters is located in Beverly Hills, California, and in one office building with its immediate owner, the News Digital Media, News Corporation belongs.

Friendster, an idea derived its name from the name of Napster, is a social networking website which provides the facility to create a profile and then fill in the data itself to then get an account on Friendster. In Friendster, we are also able to see our friends and friends of friends of friends of our friends, in addition to seeing our own friends.

Multiply.com is a social networking site with features that enable people to mutually share some media, such as photos, videos, and blogs. 

Multiply.com provide blog service. The blog post to Multiply.com can be automatically forwarded to an account LiveJournal, Blogger or Typepad

Orkut is a social networking service, allowing users to view personal and professional information, meet new friends and maintain friendships established. Here, users can also join a community that has a common interest. 

However the service was taken from its creator, Google employee Orkut Büyükkökten named. When it first appeared, Orkut will only be obtained through invitation, and opened to the public since October 2006.