Social network is a structure made up of individuals or organizations that are grouped on the basis of interdependency like values, ideas, friendship, trade, workplace, and so on. It can be a group of small communities or divisions of neighbourhood. Social networks are more popular online rather than in person. This is because there are millions of users on the Internet sharing common interests, willing to make newer connections either for business networking or for friendship. Social sites are used for online social networking.
Social networks work like an online community of like-minded users sharing common interests. They use these social sites for getting together to share and discuss their ideas and problems on subjects of their interest. Some of the commonly used social networks are Orkut, Facebook, Hi5, Classmates, MySpace, Yahoo!, 360 and so on. The commonly used social tools include blogs, bookmarking sites, search engines, RSS feeds and so on. Now-a-days business have started utilizing these free resources to market themselves for building up their image and generate traffic to their websites.