Is Palm Sunday and Easter Sunday the same celebration?

No they are not. Palm Sunday, also called Passion Sunday, in the Christian tradition, is the first day of Holy Week and the Sunday before Easter. The feast commemorates Jesus' triumphant arrival in the city of Jerusalem for Passover, where he was greeted by a crowd of people laying palm branches at his feet.

Easter Sunday on the other hand is the day Christians celebrate the resurrection of Jesus from the dead, three days after he was executed by crucifixion.