1) Facebook.comFacebook is a social networking site. Face book first started in February 2004. User can create their profile, find their friend profile and can add in to their network. In other words Facebook is a best way to be connected with our friends.
User can create their profile, find their professional friends profile and can add in to their network. User can also find the professionals to get connected to them.
3) Twitter.comTwitter is a type on social networking site. Here User can follow people and people can follow user. User can post text messages on his/her profile that goes to all its followers. On twitter you can follow any one you like to follow, it could be your friends, celebrity or any business people.
For eg. I follow some design sites, they post some new message, and i get to know all those information.