Epiphany is the day, 12 days after Christmas, when Christians commemorate the manifestation of Jesus to the Gentiles, represented by the magi or the wise men. It is based on the solar calendar, but its date is influenced by the Jewish feast of Hanukkah, which occurs around the same time of the year.
Palm Sunday is the day, the Sunday before Easter, when Christians commemorate the triumphal entry of Jesus into Jerusalem, where he was welcomed by the people with palm branches. It is based on the lunar calendar, as it depends on the date of Easter, which is determined by the Paschal full moon.
Passover is the day, 15 Nisan in the Jewish calendar, when Jews celebrate the liberation of the Israelites from slavery in Egypt, as narrated in the book of Exodus. It is based on the lunar calendar, as the Jewish calendar is a lunisolar one. Christians also recognize Passover as the context of the Last Supper and the crucifixion of Jesus.
Good Friday is the day, the Friday before Easter, when Christians commemorate the crucifixion of Jesus and his death at Calvary. It is based on the lunar calendar, as it depends on the date of Easter, which is determined by the Paschal full moon. It is also related to the Jewish feast of Passover, as Jesus was crucified during that time.
Easter Sunday is the day, the Sunday after the Paschal full moon, when Christians celebrate the resurrection of Jesus from the dead. It is based on the lunar calendar, as it depends on the date of the Paschal full moon, which is the first full moon after the spring equinox. It is also related to the Jewish feast of Passover, as Jesus rose from the dead during that time.