The Sunday before Easter is called "Palm Sunday". The name comes from a story in the Bible in which Jesus entered the city of Jerusalem. Prior to this event, Jesus and his friends roamed the countryside teaching and performing miracles, gaining a lot of recognition. The people of Jerusalem were super-excited that Jesus was coming to their city to celebrate a big religious festival. In their excitement, the people grabbed palm branches to wave around and threw their cloaks before Jesus on the road. The whole scene might have looked something like an ancient tinkertape parade. 

Today, we still commemorate Palm Sunday. It starts off a week of remembrance for Christians, often referred to as Holy Week. The week ends with the celebration of Easter, and throughout this week we mark the different events that led to Jesus' Resurrection and Easter. This means that Palm Sunday is a kind of paradoxical celebration. At worship services, there is likely a festive atmosphere. I have been part of many services where children wave palm branches and parade around the worship space shouting "Hosanna!" The paradox is that we celebrate knowing full well what came next in the story, after Jesus' triumphal entry: he was rejected, betrayed and crucified.

For more information go to

https://www.umc.org/en/content/what-is-palm-sunday#:~:text=The%20name%20comes%20from%20a,gaining%20a%20lot%20of%20recognition