Mass often refers to the entire church service in general, but is specifically the sacrament of the Eucharist. Other names for the "Eucharist" are the "Lord's Supper", the "Breaking of Bread", the "Eucharistic assembly (synaxis)", the "memorial of the Lord's Passion and Resurrection", the "Holy Sacrifice", the "Holy and Divine Liturgy" and "Holy Communion".
The term mass is commonly called in the Catholic Church, Western Rite Orthodox churches and many Old Catholic, Anglican, as well as some Lutheran churches, and Methodist churches. Some Protestants employ terms such as Divine Service or service of worship, rather than the word Mass. For the celebration of the Eucharist in Eastern churches, including those in full communion with the Holy See, other terms such as the Divine Liturgy, the Qurbono Qadisho or Holy Qurbana, and the Badarak are normal.
–Wikipedia