Thus, just as the sacraments of Baptism, Confirmation, and the Eucharist form a unity called "the sacraments of Christian initiation," so too it can be said that Penance, the Anointing of the Sick and the Eucharist as viaticum constitute at the end of Christian life "the sacraments that prepare for our heavenly homeland" or the sacraments that complete the earthly pilgrimage.
Source: Catechism of the Catholic Church (Vatican.va)