Some well-known prayers for All Souls' Day include the Catholic collect from the Mass for the dead, an invocation for the souls in purgatory, and a prayer for the holy souls in purgatory. These prayers are meant to help souls in purgatory move on.
All Souls' Day is an official holiday on the Catholic calendar. On this day, three requiem masses are celebrated: one for those praying, one for those who have passed on, and one for the pope. All Souls' Day was started in 998 as a way for Roman Catholics to remember friends and family members who have died.