What is the punch function?

CAn sombody tell me what's the punch function and how can i use it?

NOBODY KNOWS????

it a punch in punch out feature, not sure how its cause i never used it on the mpc bout you can have sequence or track and say its a little off you can use the punch feature to go over a certain part, at least thats how it worked on my four track i'm sure its simular.
someone correct me if i'm wrong

u can have it so that it records at a certain point like ede was saying. like say i got a nice drum pattern but the last bar is off, i would set the punch in at 4.0.0 then it wil record from 4.0.0 to 5.00

I don't know well english but now I've understand what is this .