Boundary delimitation usually refers to the process of drawing electoral district boundaries. However, it can also be used to denote the process of drawing voting areas (also called polling areas, districts or election precincts) for the purposes of assigning voters to polling places. The periodic delimitation of electoral boundaries is necessary in any representative system where single-member districts or uniformly small multi-member districts are used. If electoral boundaries are not periodically adjusted, population inequities develop across districts.
Countries have adopted various methods for delimiting districts. Countries that delimit districts must establish a formal structure and a set of rules for carrying out the delimitation process. In some, the choice of methods is simply a matter of historical tradition, but the delimitation can also be based on a variety of factors that may include the geographic size of the country, its physical features, or its financial resources. Different sets of districts can produce different election outcomes, and even if the underlying vote patterns remain constant, the choice of delimitation practices is important.
The Boundary Delimitation Encyclopedia topic discusses the administrative and cost implications of delimiting electoral districts for representation purposes and considers the social and political context in which delimitation takes place. It also covers the boundary setting process associated with voting areas.