Step 1: Define regional planning. Regional planning is concerned with the planning and development of a specific geographical region, which could be a metropolitan area, a state, or a group of districts.
Step 2: Identify its key feature. The defining characteristic of regional planning, as opposed to sectoral planning (developing a sector like industry) or national planning, is its focus on a particular area. It aims to address the unique problems and leverage the specific opportunities of that region. Therefore, it is an "area specific approach of development."