In geography, the three types of regions are: formal, functional and vernacular. The regions are artificial segments that allow scientists to compare areas of the world in detail.
Formal regions consist of geographic regions, cultural regions, governmental regions and economic regions. Functional regions are typically areas where a specific service is provided, such as areas of a country that a gas supplier services. Vernacular regions are subject to perception and often change based on the person defining them. For example, many people define the southern portions of the United States in different ways. Functional regions are further categorized into nodal regions and network regions.