A formal region is a geographical location, area, etc. that is inhabited by a population that has one or more consistent characteristics, physical attributes, cultural attributes, etc. in common.
Typically, formal regions are designed to work in a uniform, organized or homogeneous manner whether in terms of political systems, language, climate, laws, etc. By default, formal regions are intended to function as a single unit or a single entity while upholding a uniform ideal of an economic, social, and political system.
Since virtually everyone in a formal region functions as a part of a unified whole, certain aspects of culture, language, legislature, politics, and administration, etc. will be observed by one to overlap and be influenced by their common, immediate environment. Formal regions may be cities, states, nations, continents, etc. that have clear, official boundaries surrounding them.
Some examples of formal regions are Africa, Canada, Europe, the United States, etc.