Agglomeration
In the study of human settlements, an agglomeration is an extended city or town area comprising the built-up area of a central place (usually a municipality) and any suburbs or adjacent satellite towns.
Conurbation is a more specific term for urban clusters where the built-up zones of influence of distinct cities or towns have joined but each continues to act as an independent focus for a substantial part of the area.
A metropolitan area is an extended agglomeration or conurbation including also peripheral areas not themselves necessarily urban in character but closely bound to the urban area by employment or commerce.
See also
