Slapstick is comedy where the joke is the body: people fall over, walk into doors, throw pies, hit each other with things that look painful but are played for laughs. The word names the style, and also a show or film done in that style. It is not a rude word, and it is not the same as cruel violence. Though actually, the name comes from a real prop: two sticks slapped together to make a loud hit. That pair of sticks was used by the comic character Harlequin in old Italian theatre (the Italian name for the prop is batacchio; English built slap + stick to match the idea). The 'pain' is noise and timing, not real harm — that is why it is funny, not frightening.