Apportionment is the process by which representation in legislative bodies is distributed among the people. It may involve the assignment of a number of seats to specified areas, such as states or counties. Each area may then be divided into districts, from which representatives are elected. The reassignment of seats in a legislature among the areas represented is usually called reapportionment. The division of an area into new election districts is called redistricting. However, these terms are often used interchangeably to mean any change in an area's representation.