Urban area
There are different urban area definitions for each country. The definitions mostly depend on how populated the country is and if the definition shows a true percentage of how urbanized the country is. For example, in Poland an urban area is any place that has the status of a town, whereas in China it is any district, city, or town with a population density higher than 1500 people per square kilometer. The urban population definition for Canadian and Scandinavian countries depends on density.  If there is a house every 200 meters it is classified as urban.