A belt buckle is a fastening device used to secure the ends of a belt, typically made of leather or fabric, around the waist or hips of an individual. It consists of two main components: a metal or plastic frame and a prong. The frame is usually attached to one end of the belt, while the prong is affixed to the other end. To fasten the belt, the prong is inserted into a hole in the belt, and the tension created holds the belt securely in place around the wearer's waist or hips.