A breaker (or sometimes pneumatic drill, jackhammer or hoe ram) can be a powerful percussion hammer fitted to an excavator or a portable percussive drill powered by
compressed air (though the same type of equipment mounted to
construction machinery can also be hydraulically powered). They are used
to drill rock, break up pavement, demolish concrete structures or rocks among other things. It works
similar to a hammer and chisel, by jabbing with its bit, not rotating
it.