Painting placed on or behind the altar of a Christian church as a focus for worship. Usually depicts scenes from the life of Christ, especially the Crucifixion, or from the life of the Virgin Mary. Altarpieces are often in two or three panels (diptychs and triptychs) with the panels showing separate but related scenes. Modern artists have sometimes adopted these formats for non-religious works, either for the increased narrative scope they offer or to add a sense of spiritual weight to subjects dealing with the major issues of human life, or both.