Examples of formal regions include Canada, the Islamic world, rice fields and the Rocky Mountains. Formal regions are typically used to determine and outline government, cultural and economic areas.
In order to be considered a formal region, an area must have a specific characteristic common throughout the whole place. Formal regions can be defined by their environmental themes like mountains, natural vegetation, climate or water. Political areas can make up formal human regions whose boundaries are determined by rivers, lakes, landforms or ocean coasts.
Formal regions are different from functional regions because functional regions often have a focal point, such as a city, that is the center of the region, and the rest of the region is built around that focal point. Examples of functional regions include New York City and Los Angeles.
Vernacular regions are developed by ordinary people, often based on their language. Vernacular regions include the American Midwest and South, the Swiss Alps and southern California. Unlike the boundaries of formal regions, the boundaries of vernacular regions will vary depending on the person.
Unlike other regions, formal regions may be as large as a hemisphere or as small as a city block. In formal regions, the boundaries can be established using a particular set of criteria and are defined over time.