Palm Sunday is the final Sunday of Lent, the beginning of Holy Week, and observes the triumphant arrival of Christ in Jerusalem, days before he was crucified.

Palm Sunday is known as such because the faithful will  receive palm fronds which is used in the reenactment of Christ's arrival in Jerusalem. 

In the Gospels, Jesus entered Jerusalem riding a donkey and to the townspeople shouting praises and " Hosanna."  They also threw palms or small branches, in front of him as a sign of homage. 

Palm branches are widely recognized as symbols of peace and victory, hence their preferred use on Palm Sunday.

The use of a donkey represents the humble arrival of someone in peace, as opposed to arriving on a horse - a steed in war.

A week later, Christ would rise from the dead on the first Easter.