Redistribution is the process, used in many Commonwealth countries, by which electoral districts are added, removed, or otherwise changed. Redistribution is a form of
boundary delimitation that changes
electoral district boundaries, usually in response to periodic census results. Redistribution is required by law or constitution at least every decade in most
representative democracy systems that use
first-past-the-post or similar electoral systems to prevent geographic
malapportionment. The act of manipulation of electoral districts to favour a candidate or party is called
gerrymandering.