The Eucharist is another name for Holy Communion. The term comes from the Greek by way of Latin, and it means "thanksgiving." It is used in three ways: first, to refer to the Real Presence of Christ; second, to refer to Christ's continuing action as High Priest (He "gave thanks" at the Last Supper, which began the consecration of the bread and wine); and third, to refer to the Sacrament of Holy Communion itself. Eucharist as Communion
See Fr. Moe's video teaching on the Sacrament below.