A paten, or diskos, is a small plate, usually made of silver or gold, used to hold Eucharistic bread which is to be consecrated. It is generally used during the service itself, while the reserved sacrament are stored in the tabernacle in a ciborium.
In many Western liturgical denominations, the paten is typically either a simple saucer-like plate or a low bowl. A smaller style paten will often have a depression that allows it to securely sit on top of the chalice.
In more traditional denominations or parishes, altar servers may also use a small paten, usually attached to a short pole, which is placed under the chin of those receiving the Eucharist on the tongue; thus if the host accidentally falls, it would land on the paten rather than the floor.
The General Instruction of the Roman Missal lays down rules for patens:
"Sacred vessels should be made from precious metal. If they are made from metal that rusts or from a metal less precious than gold, they should generally be gilded on the inside."
However, provisions for vessels made from non-precious metals are made as well, provided they are "made from other solid materials which in the common estimation in each region are considered precious or noble."
Patens are also used among Anglicans and Lutherans.
In the United Methodist Church, during the The Order for the Ordination of Elders, each elder receives a stole, along with a chalice and paten, from the bishop after the part of the liturgy in which the bishop lays his hands and prays over the ministerial candidates. This is because the newly ordained elders are now able to celebrate the Sacraments, such as Holy Communion. In the Methodist service of the Holy Communion, the bread is placed upon a paten during the offertory and once again after it consecrated, specifically following the fraction. The paten, along with the claice, lays on the altar during the celebration of the Holy Eucharist.