Mark, Matthew, Luke, and Paul’s 1st letter to the Corinthians tells us how to bless and break the bread, and share the cup.
Depending on the churches we attend, the Lord’s Supper is called different things: Eucharist, Communion, Mass. This is the thickest dividing line between the Christian denominations today.
Roman Catholics and most Orthodox Christians believe in Transubstantiation: The bread and cup transforms into the body and blood of Christ. Also called Real Presence.
Anglicans and Lutherans and some Orthodox Christians believe in Consubstantiation: The bread and the cup stay the same, but when we consume them we are also consuming the spiritual body of Christ.
Presbyterians, United Churches, Baptists and many others believe in Memorial Feast: The bread and cup stay the same, we do this because Jesus asked us to do it, and the Holy Spirit is active in the community while we do this in memory of Jesus.