Nadi is a region comprising a number of cities, large towns, and other suburban areas that have merged to form one continuous urban or industrially developed area.
 Nodal regions, functional urban regions, daily urban systems, local labour-market areas (LLMAs), or travel-to-work areas (TTWAs) are considered to be special instances of a general functional region that need to fulfil some specific conditions regarding, for instance, the character of the region-organising interaction or the presence of urban cores, (Halas et al
 In the fields of physical geography, ecology, biogeography, zoogeography, and environmental geography, regions tend to be based on natural features such as ecosystems or biotopes, biomes, drainage basins, natural regions, mountain ranges, soil types

