In biology, a community is a group or collection of organisms that live together in the same location and interact with each other. Communities can be defined by either the dominant species within the community or the environment of the community.
Biological communities have many different species-to-species interactions. All the interactions affect the diversity of the community. Examples of various interactions that may be found within a community include parasitism, predation, competition, mutualism and commensalism. Many of the interactions within a community benefit numerous species, while others benefit only one species and promote high levels of competition within the community.