Best, worst and average case

Best case, worst case and average cases are three different ways of looking at how long it takes to do something or how much it might cost. Best case means it takes the least amount of time or the least amount of money. Worst case means it takes the most amount of time or the most amount of money. Average case means it takes a mixture of both less and more time or money. For example, if you were playing a game, the best case is that you'd win in the shortest amount of time, the worst case is that you'd lose in the longest amount of time and the average case is that you'd play a mixture of longer and shorter games.