A social network or a social networking service is based on the human act of building a social network, or the way we have social relations with people. Sometimes these social interactions can be built on a mutually interest or activity. The aim of a social network service is to represent this relation, usually in the form of an individual user representation (i.e.: Profile) and features that allow the user to “connect” with other users.
This connection can be in the form of basic communication (I.e.: Email, Private Messages, Blogs) or a broader sense. (Ie: Groups, Forums, and Online Communities) Social networking websites were started as early as 1985, in the generalised form of online communities, such as The WELL (1985). These early networks allowed interaction through basic form such as chat rooms and forums. Some networks were also formed by linking to other users via email addresses. Classmates.com, which started in 1995, was one of the earliest forms of this type.
Social networks can be created with different communities or demographics in mind.
Classmates.com is an example of this, the site targets school or military graduates. Xing.com and Linkedin.com both exist with business-focused people in mind. The sites allow professionals to network and view profiles of both users and of companies. There are some that have broader defined communities, such as Digg.com. Digg.com allows users to link stories, news, web pages and videos to their site where other Digg users can view and rate them, either positively (Digg) or negatively (Bury). This is not just aimed at mainstream “news” people, but also users who are interested in other “news” topics, i.e. Entertainment. Some sites do not have a mutual interest but actually allow users to create something of their own, Ning.com allows users to create their own networks, their own websites which other users can join and follow. Finally, general social networking sites exist were anyone can join, and then once they...