The word "litrugy" originally meant a "public work" or a "service in the name of/on behalf of the people. In Christian tradition, it means the participation of the People of God in "the work of God".
In every liturgical action the Holy Spirit is sent in order to bring us into communion with Christ and so to form his Body. The most intimate cooperation of the Holy Spirit and the Church is achieved in the liturgy.
Mother Church earnestly desires that all the faithful should be led to that full, conscious, and active participation in liturgical celebrations which is demanded by the nature of the liturgy.