Introduction
A community in a network is a group of nodes that are similar to each
other and dissimilar from the rest of the network. It is usually thought of as a
group where nodes are densely interconnected and sparsely connected to
other parts of the network. There is no universally accepted definition for a
community, but it is well known that most real world networks display
community structures. The goal of a community detection algorithm is to find
groups of nodes of interest in a given network. For example, a community in
the WWW network indicates a similarity among nodes in the group. Hence if
we know the information provided by a small number of web pages, then it
can be extrapolated to other web pages in the same community. Communities
in social networks can provide insights about common characteristics or
beliefs among people that makes them different from other communities. In
biomolecular interaction networks, segregating nodes into functional modules
can help identify the roles or functions of individual molecules .
