November is the month of praying for the souls of the faithful departed. It is customary to visit the cemetery and pray for the souls in Purgatory (A plenary indulgence could be gained for going to a cemetery between November 1 and November 8, or a partial indulgence any other day of the month.)
The prayers are particularly directed for the souls who are being purified in Purgatory, waiting for the day when they will join the saints in heaven. The celebration of Mass is the highest means the Church can provide for charity for the dead, but we can also relieve their sufferings through our prayers, sufferings and penances. We can particularly help the Poor Souls by doing acts and prayers that have indulgences attached to them. (Taken from https://www.catholicculture.org/culture/liturgicalyear/activities/view.cfm?id=1178)
Eternal rest grant unto them, O Lord, and let perpetual light shine upon them. May the souls of the faithful departed, through the mercy of God, rest in peace. Amen.