Pizza is a food originating in Italy and is popular all over the world. The usual practice of pizza is to cover the ketchup, cheese and other ingredients with a fermented round cake and bake it in an oven.
Pizza cutter, because the radius of other knives is small, and usually the pizza is thicker. If the pizza is cut with other knives, the whole knife will be trapped inside, and the "wheel" will not get up, and it will be dirty. The pizza knife is different, with a radius of 4.5 cm, and of course it will be handy.