What is Communion?

The Holy Eucharist or Holy Communion is a true sacrament, instituted by Christ. Christ is present in the Holy Eucharist. It is therefore to be honored and adored.  During the Mass, the bread and wine are transubstantiated into the flesh and blood of Christ so that only the appearance of bread and wine remains. The whole Christ is present and is received by the communicant.

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.  Catechism of the Catholic Church (CCC) -  1322