The Easter Triduum begins on Thursday. Maundy Thursday marks the beginning of these events: the creation of the sacrament of the Eucharist, the commemoration of the washing of the feet of the Apostles, the consecration of the holy oil, and especially the renewal of the promise made by the priest to the bishop. There was a council that specifically discussed the creed, especially the phrases that make up the creed: suffered under Pontius Pilate, was crucified, died and was buried, descended into the earth; rose on the third day.
Pontius Pilate was the governor appointed by the Roman emperor in Judea. The suffering experienced by Jesus was great both spiritually and physically. The reason Jesus Christ died was to prevent us from going to hell, to give us eternal life. Jesus Christ died for all humanity.
Good Friday is the day when Jesus Christ died, that is, he was buried in the grave. The meaning of going down to the "earth" is that the soul of Jesus Christ went down to a place called "Seoly" or Limbo, i.e. the limbo of the patriarchs, where the souls of the saints and the righteous reside, such as Abraham, Moses...
Holy Saturday is the beginning of the victory of Jesus, I am risen from the dead, Easter...