A functional region is a place that depends on the core city for the major issues. They still do require support from the external smaller cities but get most of their assistance from some of the larger most thriving cities.
A perceptual region is an area or location which people believe exists as a section of their cultural identity. These regions materialise from people's unofficial sense of place rather than scientific models, which are developed through geographic thought. Perceptual region is also referred to as a vernacular region.