The offertory (from Medieval Latin offertorium and Late Latin offerre) is the part of a Eucharistic service when the bread and wine for use in the service are ceremonially placed on the altar.
A collection of alms from the congregation, such as may take place also at non-Eucharistic services, often coincides with this ceremony.
The Eucharistic theology of Christian denominations that have a liturgical offertory may vary.
In the Roman Rite, the term "preparation of the gifts" is used in addition to the term "offertory".
Read more about Offertory: Liturgical Action, Music, Collection of Alms