Acontested election means that the losing candidate is demanding a .

A contested election means that a candidate is calling for a recount.

In many different styles of elections (state, local, national, etc.) losers can challenge the results of the election by demanding a recount. Usually, the losing candidate must be within a certain amount of votes/percentage points of the projected winner. There is also a time limit as to when this candidate can demand a recount. Usually, it needs to happen shortly after the actual election is completed.

answer; face validity;