Porcelain tiles are tiles with a water absorption rate of less than 0.5 percent that are used to cover floors and walls. They can either be unglazed or glazed.The dense, hard surface of porcelain has made polishing a viable alternative to a glazed surface. This means that a tile can be fired, then a polish cut into the surface, creating a shine without a glaze.Porcelain is much harder than ordinary ceramic tiles and is usually selected, despite its higher price etc. in areas where strength is more important, such as floors and commercial use, or in areas of high wear and hard knocks.