The chalice (from the Latin word calyx, or cup) is the cup into which wine and a little water are mixed. At the consecration of the Mass, the wine (that in the chalice as well as wine in a flagon to be poured into smaller chalices if the congregation will receive under both Species) becomes the Precious Blood of Jesus, in which Christ is truly present — Body and Blood, Soul and Divinity. The chalice is usually beautifully designed, and must be at least lined with precious metal as a sign of respect. In religious art, the chalice is sometimes shown at the foot of the cross, capturing the blood and water that flowed from the wound in Jesus’ side.
Over the chalice is laid the purificator, a fine white linen cloth that is used to wipe the lips and fingers of the priest and to cleanse the chalice after Communion. The sacristan — the person who cares for the sacred vessels and linens — cleans the purificator separately from other linens after Mass, because it holds traces of the Precious Blood.
The paten (from the Latin word for pan or plate) is a saucer-like circular dish of or lined with precious metal. At Mass, the priest places the large primary host on the paten, where at the consecration it (and other smaller hosts to be received by the congregation, held in a container called the ciborium) becomes the Body and Blood, Soul and Divinity of Jesus Christ. Where congregants receive Communion on the tongue, a server may hold a plate (also called a paten) under the communicant’s chin, so that no consecrated host or particle falls to the ground. In preparing the vessels for Mass, the paten with the large unconsecrated host is set atop the chalice, with the purificator underneath it.