“Individuals or groups linked by some common bond, shared social status, similar or shared functions, or geographic or cultural connection. Social networks form and discontinue on an ad hoc basis depending on specific need and interest.” (Barker, 1999).
“Looking at informal, transient forms of association, such as the flow of gossip, the mobilization of social movements and political campaigns, and the maintenance of patron-client relations. Such networks are groups of persons who do not necessarily know each other or share anything outside the organizing criteria of the network.” (Calhoun, 2003).
Wellman (1999) describes contemporary community networks as narrow specialized relationships rather than broadly supportive ties; as sparsely knit, loosely bounded, and frequently changing; and as supportive and sociable although spatially dispersed rather than neighborhood-based.” (Voydanoff 1999).

Barker, Robert L. (Ed.). (1999). The social work dictionary (4th Ed.). Washington, DC: NASW Press. Social Networks. (2002). In Craig Calhoun, (Ed.), Dictionary of the social sciences in politics and social sciences. UK: Oxford University Press, Inc. Internet Explorer. (16 June 2003). As defined by Voydanoff citing Wellman: Wellman, B. (1999). The network community: An introduction. In B. Wellman (Ed.). Networks in the Global Community (pp. 1-47). Boulder, CO: Westview.