The holy Eucharist completes Christian initiation. Those who have been raised to the dignity of the royal priesthood by Baptism and configured more deeply to Christ by Confirmation participate with the whole community in the Lord's own sacrifice by means of the Eucharist.
At the Last Supper, on the night he was betrayed, our Savior instituted the Eucharistic sacrifice of his Body and Blood. This he did in order to perpetuate the sacrifice of the cross throughout the ages until he should come again, and so to entrust to his beloved Spouse, the Church, a memorial of his death and resurrection: a sacrament of love, a sign of unity, a bond of charity, a Paschal banquet 'in which Christ is consumed, the mind is filled with grace, and a pledge of future glory is given to us. Catechism of the Catholic Church 1322 & 1323
Every Mass is a celebration of the Sacrament of Holy Eucharist. Within the Mass we receive the Holy Eucharist during the Communion Rite – this is often spoken of as receiving Holy Communion.
Within the church building, some of the Holy Communion under the species of bread is reserved in the tabernacle so that it may be worshiped and adored outside of Mass. This reserved Eucharist is often called the Blessed Sacrament, thus the chapel at our parish in which is the tabernacle is called the Blessed Sacrament Chapel.
Children receive the Holy Eucharist for the first time, i.e. make their First Holy Communion, usually while in the second grade after a period of preparation. This preparation is provided through the regular class work of the students in the parish school and through the grade-level classes in the parish Religious Education Program. Older children who have not received their First Communion are offered special preparation classes.