How are minor damages on cars fixed?

i had to swerve into a hedge to avoid a drunk.. the bonnet now has very minor scratches from the leaves but there is one small piece maybe about 1-2 inches long maximum where im guessing it must have been a stone/hard twig thats almost gone through the bumper.. so there is a hole. obviously i am not replacing the entire bumper for this so how are the auto repair people going to fix this? will they just paint over it or fill in the gap in? how? what exactly have i paid them for? thanks!!