Ok, so the third type of city measures a city’s geography. There are three types of cities:
1. The city consists of the downtown area and surrounding areas (downtown is also known as a Central Business District, or CBD). With a few exceptions (such as Los Angeles). This is the case in the vast majority of the USA and Canada, as well as a few European countries such as France. The city only consists of the downtown area, a few surrounding areas, and the suburbs are their own separate entities.
2. The downtown area (or multiple downtown areas) are part of the city, as well as the suburbs. The suburbs are just as much a part of the area of the downtown areas, and the borders of what’s considered to be part of the city are quite arbitrary. This is the case for Australia’s major cities, such as Sydney, or Melbourne or Brisbane. The larger of these cities include multiple local government areas
3. Cities with no downtown area. Cities with just a massive spread and no centralised core. Examples of this include Tokyo, Japan (I’m sorry, I don’t really no of any other examples). There is no downtown in Tokyo, it’s just a huge area with a huge population