Summary
Highlights
A region is a geographical unit sharing a unifying principle, which can be cultural, economic, or activity-based. Geographers define regions to study phenomena, and these regions can vary greatly in size, from sub-Saharan Africa to smaller areas within a nation like the South or Northeast of the United States.
Formal regions are geographical areas linked by common traits such as language, religion, economic prosperity, or geographical features. Examples include a region defined by Buddhist populations in East and Southeast Asia or the Everglades in Florida. These regions tend to have relatively clear boundaries.
Functional regions are organized around a shared function and a central location or 'node' where the activity is carried out. Examples include a pizza delivery zone centered on a specific restaurant or the central business district of a major city. These regions also typically have clear, though not always rigid, boundaries.
Perceptual regions are defined by people's shared beliefs and feelings about themselves and their surroundings. These regions have vague boundaries and exist in the minds of those who live there, making it difficult to draw definitive lines. The American South is an example where people share perceptions of hospitality and religiosity.
Formal and functional regions generally have distinct boundaries, while perceptual regions have vague ones. Even with formal and functional regions, boundaries can be transitional and sometimes contested. The example of Sudan splitting into Sudan and South Sudan illustrates how contested formal (religious) and functional (political/economic) regional boundaries can lead to new political entities.