A census is an official count or survey of a population. Governments often use a census to understand how many people live in different places and what basic characteristics they have.
Why a census is used
Census data can support planning for schools, roads, hospitals, public services, elections, funding, and research. It helps turn population changes into usable information.
Census versus regular survey
A census tries to count everyone in the target population, while a survey often studies a sample. In practice, both require careful methods to reduce errors.
A census is one way a country or region measures itself at a point in time.