* Actual population: The actual population is the total number of people living in a specific area at a specific time. It is distinct from the potential population that could live within that area.

* Biological population: A biological population is a group of organisms of the same species that live in the same area at the same time.

* Census population: The census population is the total number of people counted in a census.

* De facto population: The de facto population includes everyone present in an area at the time of the census.

* De jure population: The de jure population includes everyone who usually resides in an area, regardless of their physical presence at the time of the census.

* Floating population: The floating population is the population that is not permanently settled in an area. It includes individuals such as tourists, migrants, and seasonal workers.

* Legal population: The legal population is the population recognized by the government of a country or territory. It includes all citizens, permanent residents and aliens with work permits.

* Mid-year population: The mid-year population is an estimate of the population as of July 1 of a given year. It is calculated by adding the previous year's population to the net change (births minus deaths plus migration) for that year.

* Mobile population: The mobile population is the population that is constantly on the move. This includes individuals who travel frequently for work, leisure, or other reasons.

* Rural population: The rural population is the population living in rural areas, such as villages and small towns.

* Urban population: The urban population is the population living in urban areas, such as cities and large towns.

* World population: The world population is the total number of people living on Earth.