This chapter examines communities as a special type of corporate unit. The macrolevel environment of communities—patterns of institutional differentiation and stratification, ideologies and meta-ideologies, and mechanism of structural and cultural integration—is first examined in detail. Then mesolevel environments of other communities, organizations, groups, and categoric units are explored, with particular emphasis on categoric-unit distributions within and between communities. Next, microlevel environments of communities are outlined, again with emphasis on inequality among categoric units distributed in neighborhoods of communities. Internal community dynamics of growth and size, differentiation within and between communities, and boundary dynamics are delineated. The chapter closes with abstract principles on the dynamics of communities within macro- and microsociocultural environments, fields, and niches.