A census is an official count of all the residents in the United States. This information is used to determine the number of seats each state has in the House of Representatives and also determines how the federal funds are distributed throughout the United States. The decennial U.S. census is the population count that is Constitutionally required to occur every ten years. The information obtained through it is the basis for reapportionment and redistricting in Congress. This information also affects the allocation of government funds, state apportionment, and local planning and investment.