No. 1357 to 1359, page 342 of the Catechism of the Catholic Church, Libreria Editrice Vaticana: Urbi Et Orbi Communications:
: We carry out this command of the Lord by celebrating the memorial of his sacrifice. In so doing, we offer to the Father what he has himself given us: the gifts of his creation, bread and wine which, by the power of the Holy Spirit and by the words of Christ, have become the body and blood of Christ. Christ is thus really and mysteriously made present.
&bsp; We must therefore consider the Eucharist as:
The Eucharist, the sacrament of our salvation accomplished by Christ on the cross, is also a sacrifice of praise in thanksgiving for the work of creation. In the Eucharistic sacrifice the whole of creation loved by God is presented to the Father through the death and the Resurrection of Christ. Through Christ the Church can offer the sacrifice of praise in thanksgiving for all that God has made good, beautiful, and just in creation and in humanity.
From the Baltimore Catechism No. 4; Benziger Brothers, Inc and Tan Books and Publishers, Inc. Nos. 252-256, Page 207
Q: When are we bound to receive Holy Communion?
A: We are bound to receive Holy Communion, under pain of mortal sin, during the Easter time and when in danger of death.
Q: Is it well to receive Holy Communion often?
A: It is well to receive Holy Communion often, as nothing is a greater aid to a holy life than often to receive the Author of all graces and the Source of all good.
Q: What should we do after Holy Communion?
A; After Holy Communion we should spend some time in adoring Our Lord, in thanking Him for the graces we have received and in asking Him for the blessings we need.