Porcelain tiles or ceramic tiles are porcelain or ceramic tiles commonly used to cover floors and walls, with a water absorption rate of less than 0.5 percent. The clay used to build porcelain tiles is generally denser. They can either be glazed or unglazed. Porcelain tiles are one type of vitrified tiles and are sometimes referred to as porcelain vitrified tiles.
Historically, porcelain was not the usual material for tiles, which were much more often made of earthenware (terracotta) or stoneware. The first porcelain tiles were made in China, for example in the 15th-century Porcelain Tower of Nanjing (now largely destroyed). Here the tiles were used for walls, which long remained typical. In Europe, a few rooms were made in palaces of porcelain plaques, often with forms in high relief. These were made by Capodimonte porcelain and Real Fábrica del Buen Retiro among others.
Although porcelain has now been widely used for making tiles for many years, modern production methods and quantities have made porcelain tiles available for the average householder in recent years.