From the Greek word λειτουργια, which can be transliterated as "leitourgia," meaning "the work of the people," a liturgy comprises a solemn religious ceremony, following a carefully prescribed formal ritual. The word is most commonly applied to the religious ceremonies of some Christian churches. In particular, the Catholic Mass is a liturgy.

A partial list of liturgical churches and some examples of their liturgies (past and present)

Frequent liturgical practice

Most Protestant Christian denominations, while often following a fixed "order of worship," do not adhere to a liturgy in the strict sense of the word.

Eastern Orthodox churches call the liturgy in which the Eucharist is celebrated and served the Divine Liturgy. This is generally comparable to the Roman Catholic Mass, although some details are different. This can also refer to the detailed rubrics for this ceremony; two of the best known are the "Divine Liturgy of St. John Chrysostom and the "Divine Liturgy of St. Basil the Great

Matins refers to prayers generally said in the morning, without the Eucharist. Vespers refers to prayers generally said in the evening, without the Eucharist. Great Vespers is an extended vespers service used on the eve of a major Feast day, or on the evening before the Eucharist will be celebrated.