Affusion (la. affusio) is a method of baptism where water is poured on the head of the person being baptized. The word "affusion" comes from the Latin affusio, meaning "to pour on". Affusion is one of four methods of baptism used by Christians, which also include total submersion baptism, partial immersion baptism, and aspersion or sprinkling. Christian denominations that baptize by affusion do not deny the legitimacy of baptizing by submersion or immersion; rather, they consider that affusion is a sufficient, if not necessarily preferable, method of baptism.