A prize-giving is a ceremony at which people are given prizes, especially at a school. Picture a hall, parents on chairs, a teacher reading names, and a student walking up for a cup, a book, or a certificate. It is the event, not the prize itself. The word feels British and a little old-school in a warm way; American schools more often say awards ceremony. Sports clubs and music schools hold prize-givings too. You go to a prize-giving; you win a prize at one. Though actually, some schools now call the same afternoon an awards evening, so you may meet both names for one sitting.