Abstract Ecological communities are the set of potentially interacting species co‐occurring at one place. The field of community ecology investigates both the pattern and processes of ecological communities, the structure of communities, and what factors and processes determine that structure. The three main approaches to these questions are comparing naturally occurring variations in communities across both space and time, comparing responses to experimental manipulations, and theoretical modeling. As a field, community ecology partially overlaps with population ecology, landscape ecology, ecosystem ecology and biogeography.