From a statistical point of view, in Spain, a singular population entity (in Spanish: entidad singular de población)[1] is defined as "any inhabited area within a municipality, inhabited or exceptionally uninhabited, clearly differentiated within that municipality and that is known by a specific name that identifies it without the possibility of confusion", according to the definition of the National Statistics Institute.
Each singular population entity has a category that is the qualification granted, or traditionally recognized, such as city, town, lugar or village, and in the absence thereof, the one that responds to its origin and characteristics, such as baserri, settlement, barrio, monastery, tourist center, residential area, urbanization and others.
Similarly, a population nucleus corresponds to one of the following categories: city, town, lugar or hamlet, settlement, barrio, residential area, urbanization.
Some collective population entities receive, according to the legislation of each Autonomous Community, the consideration of local Entity of territorial scope inferior to the municipality foreseen in the Local Regime Law;[5] these entities according to this law do not have legal personality, and according to the autonomous legislation can receive their own denominations: in the autonomous legislation they can receive other denominations such as hamlets, parishes, villages, barrios, elizates, concejos, pedanías, annexed places and other analogous ones.
The municipalities must review, at least once a year, the list of entidades and population nuclei and send it to the National Statistics Institute, which publishes it annually.