Ecumenopolis - a theoretical construction in which the entire area of Earth that is taken up by human settlements, or at least, that those are linked so that to create urban areas so big that they can shape an urban continuum through thousands of kilometers which cannot be considered as a megalopolis. As of the year 2009, the United Nations estimated that for the first time more than 50% of the world’s populations lived in cities, so if these were linked, the total population of this area would be about 3,400,000,000 people as of 2010.

Megalopolis - a group of conurbations, consisting of more than ten million people each.

Conurbation - a group of large cities and their suburbs, consisting of three to ten million people.

Metropolis – a large city and its suburbs consisting of multiple cities and towns. The population is usually one to three million.

Large city – a city with a large population and many services. The population is <1 million people but over 300,000 people.

City – a city would have abundant services, but not as many as a large city. The population of a city is between 100,000 and 300,000 people.[citation needed]

Large town – a large town has a population of 20,000 to 100,000.

Town – a town has a population of 1,000 to 20,000.

Village – a village is a human settlement or community that is larger than a hamlet but smaller than a town. A village generally does not have many services, most likely a church or only a small shop or post office. The population of a village varies; the average population can range from hundreds to thousands.

Hamlet – a hamlet has a tiny population (<100) and very few (if any) services, with only a few buildings.