Urban hierarchies in the world: in a world that is becoming increasingly globalised and interconnected, the larger and most important cities have an influence that goes beyond the borders of the country they are located in.
- World metropolises: these are large urban centres that integrate other smaller cities within their metropolitan areas.
- Megacities: according to the UN, these are cities with more than 10 million inhabitants.
- Megalopolies: these are large-scale urban agglomerations formed by the metropolitan areas of several cities being joined by their transport system.
- Global cities: due to globalisation, these cities have a global influence as regards certain activities, like information technology, transport, finance and trade.
Continental and regional cities: are cities with large populations that may be similar to the populations of world cities and megacities, but their influence is focused on smaller continental and regional areas.
- Continental areas: these cities govern very large areas and their influence can be left across a whole continent of part of one.
- Regional cities: These cities have a supranational influence, covering large areas of the continent.
Medium-sized cities: have most, if not all, the services found in larger cities, but their smaller size makes them more accessible to their inhabitants.