Notes:
The invention of a white pottery glaze suitable for painted decoration, by the addition of an oxide of tin to the slip of a lead glaze, was a major advance in the history of pottery. The invention seems to have been made in Iran or the Middle East before the ninth century. A kiln capable of producing temperatures exceeding 1,000 °C (1,830 °F) was required to achieve this result, the result of millennia of refined pottery-making traditions. The term is now used for a wide variety of pottery from several parts of the world, including many types of European painted wares, often produced as cheaper versions of porcelain styles.
English generally uses various other terms for well-known sub-types of faience. Italian tin-glazed earthenware, at least the early forms, is called maiolica in English, Dutch wares are called Delftware, and their English equivalents English delftware, leaving "faience" as the normal term in English for French, German, Spanish, Portuguese wares and those of other countries not mentioned (it is also the usual French term, and fayence in German). The name faience is simply the French name for Faenza, in the Romagna near Ravenna, Italy, where a painted majolica ware on a clean, opaque pure-white ground, was produced for export as early as the fifteenth century.
Hispano-Moresque ware dish from Manises, 15th century, the earliest type of European faience.
Technically, lead-glazed earthenware, such as the French sixteenth-century Saint-Porchaire ware, does not properly qualify as faience, but the distinction is not usually maintained. Semi-vitreous stoneware may be glazed like faience. Egyptian faience is not really faience, or pottery, at all, but made of a vitreous frit, and so closer to glass.
In English 19th-century usage "faience" was often used to describe "any earthenware with relief modelling decorated with coloured glazes", including much glazed architectural terracotta and Victorian majolica, adding a further complexity to the list of meanings of the word.