Regions in geography are defined areas that share certain characteristics; it can either be a natural or artificial region that differs in size. Some of the examples of natural regions include similarities in climate, landscapes, and wildlife. On the other hand, artificial regions may be characterized by religion, governmental systems, or linguistic characteristics. Geographers may group regions based on the characteristic. However, as boundaries change over time, regions are constantly changing. A region is not self-defined or nature-given; instead, it is an artifact of selection, choosing what to include and excluding the rest, which is irrelevant to the concept.

Formal Regions

• A geographical area that has a uniformity or homogeneity concerning some selected criteria.
• Early definitions referred to physical factors such as relief, climate, soil, and vegetation.
• Economic factors, later on, such as industrial and agricultural regions.
• Social and political criteria can also be used for defining formal regions, so for example, linguistic or political regions.
• Some formal regions have well-defined boundaries through which it becomes very easy to identify, such as countries, states, or areas like Europe, Africa, USA, and Canada or Indian states like Assam and West Bengal.

Functional Regions

• These regions are connected through functional relationships and are also termed the nodal or polarized regions.
• They consist of different units, which are functionally linked such as towns, cities, and villages.
• A functional region may consist of a combination of physical or political regions that are united by common function. For example, the Pune Metropolitan Region consists of various villages, towns, and cities.
• These regions work socially and economically as one unit.
• There are various flows between the parts, which consist of commuting or shopping trips.

Planning Regions

• As production, trade, and development have gotten complex, then planning regions are required.
• Planning regions can be formed from both formal and functional regions.
  Examples include economic planning regions that can be considered to be formal regions comprising homogeneous factors such as unemployment. Others are functional regions like metropolitan areas containing flows between cities and towns.