Order of Mass is an outline of a Mass celebration, describing how and in what order liturgical texts and rituals are employed to constitute a Mass.The expression Order of Mass is particularily tied to the Roman Rite where the sections appearing under that title in the Roman Missal also contain a set of liturgical texts that recur in most or in all Eucharistic liturgies (the so-called invariable texts, or ordinary of the Mass), while the rubrics indicate the rituals, and the insertion points of the variable texts known as the proper of the Mass.