The difference is in the composition and durability of the tile. Although ceramic and porcelain tile are both made from clay and other minerals, the clay used to make porcelain tile is more refined and fired at much higher temperatures than ceramic tile. As a result, porcelain tile is extremely dense and less porous so it's more resistant to moisture, stains, and water absorption. Although ceramic tiles are less expensive and highly recommended for interior floors and walls, porcelain tiles are more desirable due to its durability and resistance to chipping and scratching, especially for areas that endure heavy traffic.