The regional level encompasses a larger geographical area than just one city, often including multiple cities, towns, and their surrounding regions.
Related terms
Metropolitan Area: A metropolitan area consists of a central city along with its surrounding suburban areas, connected economically and socially.
Functional Region: A functional region is an area organized around a particular focal point or economic activity.
Urban Cluster: An urban cluster refers to an area where there are concentrations of densely populated urban spaces outside traditional city boundaries.