A retable is a framed altarpiece, raised slightly above the back of the altar or communion table, on which are placed the cross, ceremonial candlesticks and other ornaments.
Foreign usage of the term, as in French, is different, and where the word is kept with this foreign application, the distinction should be observed. The Medieval Latin retrotabulum (modernized retabulum) was applied to an architectural feature set up at the back of an altar, and generally taking the form of a screen framing a picture, carved or sculptured work in wood or stone, or mosaic, or of a movable feature such as the Pala d'Oro in St Mark's Basilica, Venice, of gold, jewels and enamels. The foreign retable is, therefore, what should in English be called a reredos, though that is not in modern usage a movable feature.
The cognate Spanish term, retablo, generally refers more broadly to any two-dimensional depiction (usually a framed painting) of a saint or other Christian religious figure, as contrasted with a bulto, a three-dimensional statue of same.