Social Network

Definition: a Social Network is a relational structure made up of a set of actors (such as individuals or organizations) and the dyadic ties and interactions between these actors.
A SN is a social sciences model to study relationships between individuals, groups, organizations, or even entire societies (social units).
It is also used to indicate an online service or website that facilitates the building of social relations among people who share backgrounds, activities, interests, or connections (e.g. Facebook, Twitter).

More on social networks. More on networking: Network Organization, Professional Networking.