The practice of burying the dead, contrasting with cremation and exposure. Burial may be in a dug grave, or in a natural or built chamber - and may be simple or elaborate. Terms commonly used to describe it are: extended (with spine and leg bones more or less in a straight line), flexed (with the leg bones bent, but by less than 90 degrees) or crouched (with the hip and knee joints bent through more than 90 degrees). Extended burials may be supine (on the back), prone (on the face), or on the side. Primary inhumation is the initial burial of a deceased individual. Secondary inhumation is the practice of removing the remains of the deceased individual from the pyre to the grave.