Foley

Foley is the process of recording sounds after the film has been filmed and adding or enhancing audio for the film. When filming some sound isn't  picked up or not loud enough, so foley artist will recreate the sounds in a quiet room to then put over the film.
Foley  was created in the 1920's by Jack Donovan Foley, his first use of foley in a film was in "show Boat" which is a musical. Foley allows SFX to be added in post production that enhance the soundscape of the film.
Foley sound are recorded in a recording studio. There are three main categories, feet, props and cloth.
Foley also prevents any copyright issues since all sounds will be produced and created in-house.