The sacrament of the Holy Eucharist, is a sacrament instituted by Christ at the Last Supper when he told his Apostles: " This is my body given for you; do this in remembrance of me" (Luke 22:19) While the other sacraments (Baptism, Confirmation, Holy Orders, Holy Matrimony, Anointing of the Sick, Penance) give us grace, the Holy Eucharist gives us not just but grace, but also the author of grace, Jesus, God and Man. It is the center of all else the Church has and does.
...coming from the Church herself