In the United Kingdom (UK), each of the electoral areas or divisions called constituencies elects one member to a parliament or assembly, with the exception of European Parliament constituencies which are multi member constituencies.
Within the United Kingdom there are five bodies with members elected by electoral districts called "constituencies" as opposed to "wards":
Between 1921 and 1973 the following body also included members elected by constituencies:
Electoral areas called constituencies are also used in elections to the European Parliament. (See European Parliament constituencies.)
In local government elections (other than for the London Assembly) electoral areas are called wards or electoral divisions.
House of Commons, Northern Ireland Assembly, Scottish Parliament and Welsh Assembly constituencies are designated as either county or borough constituencies, except that in Scotland the term burgh is used instead of borough. Since the advent of universal suffrage, the differences between county and borough constituencies are slight. Formerly (see below) the franchise differed, and there were also county borough and university constituencies.
Borough constituencies are predominantly urban while county constituencies are predominantly rural. There is no definitive statutory criterion for the distinction; the Boundary Commission for England has stated that, "as a general principle, where constituencies contain more than a small rural element they should normally be designated as county constituencies. Otherwise they should be designated as borough constituencies." In Scotland, all House of Commons constituencies are county constituencies except those in the cities of Glasgow, Edinburgh, Aberdeen, Dundee and three urban areas of North Lanarkshire.