Social Networks

=Definition= Social networks are "social structures made of nodes (which are generally individuals or organizations) that are tied by one or more specific types of relations (such as financial exchange, friendship, hate, trade, web links, or airline routes)", which can be either physical or virtual (cf. Wikipedia). Physical relations are mostly analyzed in sociology, while virtual relations are of interest in social software such as MySpace or StudiVZ, which allow users to manage their (virtual) relation via the Internet: In order to do so, user may create and manage profiles (including their CV, interests, contacts, pictures, videos) and decide when and to whom they want to provide their data to.

By analyzing social networks as well as other relations and communication structures, communities can be identified automatically or semi-automatically.

=Discussion=
 * Communities have social networks!
 * Social networks are one way to build communities (e.g. via  social software) or to find  communities
 * Social relations are a sub-class of practices!