Eucharist (Catholic Church)
"At the Last Supper, on the night he was betrayed, our Savior instituted the Eucharistic sacrifice of his Body and Blood." (Catechism of the Catholic Church 1323)
Eucharist in the Catholic Church refers to both the celebration of the Mass, that is, the Eucharist liturgy, and the bread and wine which after the consecration are transubstantiated (changed in substance) into the body and blood of Jesus Christ, Lord and God, a declaration formulated by the Council of Trent with an anathema against anyone who denied this. Blessed Sacrament is a devotional term used in the Roman Catholic Church to refer to the Eucharistic species (the Body and Blood of Christ).
Read more about Eucharist (Catholic Church): New Testament Foundations, Historical Development, Eucharistic Liturgy, Transubstantiation, Minister of The Sacrament, Receiving The Eucharist, Matter For The Sacrament, Nuptial Mass and Other Ritual Masses, Adoration of The Blessed Sacrament and Benediction, Communion of Reparation, Old Testament Prefigurings