The celebration of the Eucharist or Mass or Holy Sacrifice, as we know it, begins with the entrance or opening hymn and ends with the consecration hymn. It unfolds in two main periods, but its content is structured as one: first, the gathering or opening of the celebration and second, the celebration of the Sacrifice or liturgy of the Eucharist... Catechism on the Eucharist, with P. Justolat Rafaralahimboa.