Final answer:
A formal region is defined by a common characteristic shared across an area, which can be cultural, political or linguistic, while a functional region is based on a shared function or relationship, such as service areas for businesses or media broadcasts.
Step-by-step explanation:
A formal region is defined by a common characteristic, such as a government, language, or a cultural trait that is prevalent in the area. For instance, an area where most individuals adhere to the Church of Jesus Christ of Latter-Day Saints can be considered a formal region, sometimes referred to as the "Mormon Region." Moreover, a formal region can also refer to political entities with official boundaries like states or countries, or even a school district. Formal regions can range from being homogenous with the characteristic uniformly spread, or having a core where the characteristic is more intense and a periphery where it is less pronounced.
Contrastingly, a functional region is characterized by a shared relationship or function among areas, such as the coverage area of a newspaper or a network of radio stations airing the same broadcasts. Functional regions are often organized around a node or a central point, and their extent is defined by the function they serve. If the functional service ceases to exist, so does the region. An example is the delivery area of a local pizza shop, which is a functional region defined by the service it provides.