A powerplay is a playing condition imposed in certain types of limited-overs matches; it is not part of the Laws.

Currently it is the name of each of three periods, one of 10 overs and two of 5, in which restrictions are placed of the position of fielders - for example that there must be a minimum number of fielders within a certain distance of the pitch at the moment each ball is delivered.
The first of these three powerplays is usually the first ten overs of the innings. The other two may be employed at the fielding captain's discretion, and can be taken consecutively if he wishes, but must be used up within the total overs allowed for the innings.

In T20 cricket, the powerplay usually lasts for the first 6 overs of each innings