The Mass is the central liturgical service of the Eucharist in the Catholic Church, in which bread and wine are consecrated and become the body and blood of Christ. As defined by the Church at the Council of Trent, in the Mass "the same Christ who offered himself once in a bloody manner on the altar of the cross, is present and offered in an unbloody manner".The Church describes the Mass as the "source and summit of the Christian life", and teaches that the Mass is a sacrifice, in which the sacramental bread and wine, through consecration by an ordained priest, become the sacrificial body, blood, soul, and divinity of Christ as the sacrifice on Calvary made truly present once again on the altar. The Catholic Church permits only baptised members in the state of grace (Catholics who are not in a state of mortal sin) to receive Christ in the Eucharist. Many of the other sacraments of the Catholic Church, such as confirmation, holy orders, and holy matrimony, are now generally administered within a celebration of Mass, but before the Second Vatican Council were often or even usually administered separately. The term "Mass" is commonly used to describe the celebration of the Eucharist in the Latin Church, while the various Eastern Catholic liturgies use terms such as "Divine Liturgy", "Holy Qurbana", and "Badarak",in accordance with each one's tradition. Pope Benedict XVI's 2007 motu proprio Summorum Pontificum authorized under certain conditions, more widely than before, continued use of the 1962 form of the Roman Rite, which it called the Extraordinary Form of the Roman Rite, while it called the post–Vatican II form promulgated by Pope Paul VI in 1969 and revised by Pope John Paul II in 2002 the Ordinary Form. On 16 July 2021 Pope Francis in his apostolic letter Traditionis custodes restricted the celebration of the Tridentine Mass of the Roman Rite and declared that "the liturgical books promulgated by Saint Paul VI and Saint John Paul II, in conformity with the decrees of Vatican Council II, are the unique expression of the lex orandi of the Roman Rite." The term "Mass" is derived from the concluding words of the Roman Rite Mass in Latin: Ite, missa est ('Go, it is the dismissal', officially translated as 'Go forth, the Mass is ended'). The Late Latin word missa substantively corresponds to the classical Latin word missio. In antiquity, missa simply meant "dismissal". In Christian usage, however, it gradually took on a deeper meaning. The word "dismissal" has come to imply a mission. ... https://www.youtube.com/watch?v=Fzh-A-J5Uwk

... https://www.youtube.com/watch?v=_pPHtAfQWqA