Palm Sunday
On this Sunday, we celebrate Jesus' triumphal entry into Jerusalem. The crowd welcomed him as a king and layed on the ground clothes, and palm branches. The sing, ""Hosanna! Blessed is he who comes in the name of the Lord, even the King of Israel!"
There are two parts to today's celebration.

First we gather in the courtyard to bless the palms and read the gospel after which we begin the procession with palms. 
Later in the Church we celebrate Mass as usual with the passion narrative read as the gospel of today. 

With this, begins the Holy Week and from Thursday the triduum. Officially lent ends on Wednesday of the Holy Week.