According to Catholic Encyclopedia, “liturgy often means the whole complex of official services, all the rites, ceremonies, prayers, and sacraments of the Church, as opposed to private devotions. In this sense we speak of the arrangement of all these services in certain set forms (including the canonical hours, administration of sacraments, etc.), used officially by any local church, as the liturgy of such a church — the Liturgy of Antioch, the Roman Liturgy, and so on. So liturgy means rite; we speak indifferently of the Byzantine Rite or the Byzantine Liturgy. In the same sense we distinguish the official services from others by calling them liturgical; those services are liturgical which are contained in any of the official books (see LITURGICAL BOOKS) of a rite. In the Roman Church, for instance, Compline is a liturgical service, the Rosary is not.”
It is an external manifestation of our faith of which we would like to convey our worship to the one true God that also reflect the proper meaning of which it is intended. Therefore, it is necessary to enlighten us in a more concrete ways as it is presented to us in the present time as a true manifestation of our beliefs and culture.