IV. The Liturgical Celebration of the Eucharist

1348
All gather together. Christians come together in one place for the Eucharistic assembly.
At its head is Christ himself, the principal agent of the Eucharist. He is high
priest of the New Covenant; it is he himself who presides invisibly over every
Eucharistic celebration. It is in representing him that the bishop or priest
acting in the person of Christ the head (in persona Christi capitis) presides
over the assembly, speaks after the readings, receives the offerings, and says
the Eucharistic Prayer. All have their own active parts to play in the
celebration, each in his own way: readers, those who bring up the offerings,
those who give communion, and the whole people whose “Amen” manifests
their participation.

From The Catechism of the Catholic Church – rosary.team

Original Link: https://www.vatican.va/archive/ENG0015/__P40.HTM