A social network service is a service made to create interactive social networks for people who share common interests. These social network services are primarily web-based and offer various ways for people to interact.

The idea that computers can communicate through networking marked the advent of a social interaction network. The early efforts in supporting social networks through computer communication include EIES, bulletin board services, LISTERV, ARPANET, and Usenet. These user networks were first used for discussion, electronic mailing, and defence and security purposes.

Classmates.com and SixDegrees.com, introduced in 1995 and 1997 respectively, were among the early social networking websites which focused on ties with former school mates and indirect ties with any one. These websites offer user profiles so members who have similar interests can be searched, and messages can be sent to any user as well. The development of these websites became very popular, but they were not profitable and eventually ceased operation.

In 1999, websites developed by Epinions.com and those made by Jonathan Bishop as well as other UK sites were trust-based. These websites were friendship-based and allowed users to view and find friends, as well as allow them to personalise the content and connectivity of their page. Between 2002 and 2005, Friendster, MySpace, and Bebo become popular to users worldwide, whereas MySpace became the most viewed page, as reported by Google in 2005. In 2004, Facebook emerged to compete with other social network websites and has experienced rapid user growth. In 2006, Facebook was offered to communities outside the US and allowed users to personalise their page with graphics and add-on applications.