Known liturgically as the “Commemoration of All the Faithful Departed”, All Souls’ Day is often seen as a continuation and extension of the All Saints’
Day observances conducted the day before. While All Saints’ Day is dedicated to those who are in heaven, All Souls’ Day is a day of prayer for those who have died but have not yet reached heaven. The custom of placing lit candles on the graves of deceased relatives on All Saints’ Day often continues into All Souls’ Day. ~ Catholic Online