The Eucharist in the Catholic Church is the celebration of Mass, the eucharistic liturgy. The term Eucharist is also used for the bread and wine when transubstantiated (their substance having been changed), according to Catholic teaching, into the body and blood of Jesus Christ. Church teaching places the origin of the Eucharist at the Last Supper of Jesus with his disciples, at which time he took bread and gave it to his disciples, telling them to eat of it, because it was his body. Then he took a cup and gave it to his disciples, telling them to drink of it because it was the cup of the new covenant in his blood.
If you have any questions about First Communion preparation, please contact Marisa Ferrara, Coordinator of Elementary Formation & First Sacraments at Marisa.firstname.lastname@example.org