Altar Server Schematic
The first part of the Mass (the Mass of the Catechumens) contains the Introit and the Collect prayers, said by the priest. For the altar server, the main action to remember is to transfer the Missal from the Epistle side to the Gospel side.
The next part of the Mass is the Offertory. The altar server will present the wine and the water to the priest. Then he will give the water and the finger towel for the Lavabo. The priest says the Preface and the Sanctus.
The next part is the Consecration. When the priest spreads his hands over the offerings and says “Hanc igitur...”, the altar server rings the bell, genuflects in the middle, and goes up the steps. During the consecration of the Host and the chalice, the bell is rung a number of times as indicated.
The last part is the Communion. After the priest receives the Host and removes the pall from the chalice, the altar server gets the Communion paten, genuflects in the middle, and goes up the steps to receive Communion.
At the end of the Communion, the ablutions are done. Then the altar server transfers the Missal from the Gospel side to the Epistle side.