This is the image-bearing object which is placed upon an altar in a Christian church. Altarpieces usually form the focus of devotion for worshippers and are normally decorated by painters and/or sculptors.
They can vary considerably in size and in complexity of construction, ranging from simple dossals to huge polyptychs. The range of imagery with which they are decorated is also vast. Sometimes complex narratives which can be 'read' are depicted; on other occasions static iconic representations are shown.