In the mainland of the People's Republic of China, the term is usually used for the urban administrative division. These divisions are found below the district level. A subdistrict level may exists in some cities. They are also called streets. The naming may be different from one city to another. Neighbourhoods usually have 2,000 to 10,000 families. Within neighbourhoods, families are grouped into smaller groups of 100 to 600 families. These smaller groups are supervised by a residents' committee. These groups are often broken down into even smaller groups of fifteen to forty families. In most urban areas of China, neighbourhood, community, residential community, residential unit, residential quarter have the same meaning.