The paschal candle is usually blessed at the beginning of the Easter Vigil ceremonies and is placed on a special candlestick near the altar or ambo.
During the ceremony, five grains of incense representing Christ’s wounds are inserted in the form of a cross. An alpha above the cross and an omega below (the first and last letters of the Greek alphabet) indicate that Christ is the beginning and end of all. The current year is traced on the four sides of the cross.
The candle remains in the presbytery during the 50 days of Easter season and is lit for all liturgical offices. After Pentecost it is left next to the baptismal font.
During the year it is lit during all baptisms and funeral services; the candle is placed next to the casket during the funeral Mass. In this way it symbolizes baptism as a death and resurrection in Christ, and also testifies to Christian certainty in the resurrection of the dead as well as to the fact that all are alive in the risen Christ.
https://www.ewtn.com/library/Liturgy/zlitur169.htm