Pruning - artificial intelligence:
Recall which pruning a search space means deciding that there certain branches to should not be explored. Moreover if an agent knows for sure that exploring a certain branch will not affect its choice for a particular move, so after that branch can be pruned with no concern at all because there no effect on the outcome of the search for a move or the speed up in search may mean that spare depths can be searched.
However require a minimax approach, either an entire search tree or for in a cutoff search, so then there are often many more branches in which pruned here we find out such fairly quickly which is one the good value down a whole branch is not as better as the best value from a branch we have before now explored. It like in pruning is defines as alpha-beta pruning.