Social network analysis (SNA) views [[social relationship]]s in terms of [[network theory]] consisting of ''nodes'' and ''ties'' (also called ''edges'', ''links'', or ''connections''). [[Node (computer science)|Nodes]] are the individual actors within the networks, and ties are the relationships between the actors. The resulting [[Graph (mathematics)|graph]]-based structures are often very [[Complex network|complex]]. There can be many kinds of ties between the nodes. Research in a number of academic fields has shown that social networks operate on many levels, from families up to the level of nations, and play a critical role in determining the way problems are solved, organizations are run, and the degree to which individuals succeed in achieving their goals.

In its simplest form, a social network is a map of specified ties, such as friendship, between the nodes being studied. The nodes to which an individual is thus connected are the social contacts of that individual. The network can also be used to measure [[social capital]] – the value that an individual gets from the social network. These concepts are often displayed in a social [[network diagram]], where nodes are the points and ties are the lines.