Good Friday is the day on which Catholics commemorate the crucifixion of Jesus Christ. Catholics are joined by almost all other Christians in solemn commemoration on this day. 
Traditionally, there is no Mass and no celebration of the Eucharist on Good Friday. A liturgy may still be performed. Baptism, penance, and anointing of the sick may be performed, but only in unusual circumstances. Church bells are silent. Altars are left bare.