Altar - Oxford Definition

Originally the elevated table or podium on which sacrificial offerings to the deities were placed. In Christian churches the altar is consecrated for the celebration of the Sacrament. The principal or high altar is at the east end of the church, other altars devoted to particular saints may be in the side chapels. From the 6th century onwards altars were of stone and often enclosed relics in the altar-slab. The Reformation encouraged the use of wooden Communion tables instead.