The use of Internet technologies to link together users of the Internet who have common interests. Typical technologies that are used in social networking include Wikis, blogs, instant messaging and podcasts. A good example of a social networking Web site is Facebook. This allows users to post details about themselves, add friends and send messages to those friends. This is an example of a generic social networking site; there are other sites which are more focussed, for example sites which allows classmates from school or university to keep in contact with each other. Another example is that of medical social networking sites which link up health practitioners or link up patients, for example cancer patients.