All porcelain tiles
are ceramic tile; however, not all ceramic tiles are porcelain. Specifically, porcelain tiles are ceramic tiles with a water absorption rating of less than 0.5%. This is why unglazed porcelain tiles can be used outdoors in exterior settings, as well as indoors.
Their low water absorption rating keeps them stable during freeze-thaw cycles. Porcelain tiles are made from fine clays, quartz, and feldspar and are fired at a higher temperature resulting in a denser and more water resistant tile than standard ceramic tile.