A cup is for a boys mid section mostly used for people who play sports like baseball or football and if you get hit there it wont end your bloodline bc you have something infront of it you need sports underwear for it so you can slide it in a pocket for it to sit in. (I once was hit in the b@ll s@ck with a baseball but luckily i had a cup on so i didnt feel any pain) but yeah its protection for your s@ck