Technically speaking, liturgy is a subset of ritual. When ritual is undertaken to participate in a divine act or assist a divine action, it is liturgy. If the ritual does not have this purpose it is not liturgy but only ritual. Thus, the word, sometimes rendered by its English translation "Service or Divine Service", refers to a formal ritual, which may or may not be elaborate, enacted by those who understand themselves to be participating in a divine action, such as the Eastern Orthodox Divine Liturgy (Greek: Θεία Λειτουργία), Catholic Mass, the Eucharist or Mass (Anglican Communion). A daily activity such as the Muslim salah and Jewish synagogue services would be ritual but not liturgy. If the Temple were re-established, the ritual undertaken by the Judaic priesthood within the Temple would be liturgy.
The word liturgy, derived from the technical term in ancient Greek (Greek: λειτουργία), leitourgia, which literally means "work of the people" is a literal translation of the two words "litos ergos" or "public service". In origin it signified the often expensive offerings wealthy Greeks made in service to the people, and thus to the polis and the state. Through the leitourgia, the rich carried a financial burden and were correspondingly rewarded with honours and prestige. The leitourgia were assigned by the polis, the State and Roman Empire and became obligatory in the course of the 3rd century A.D. The performance of such supported the patron's standing among the elite and the popular at large. The holder of a Hellenic leitourgia was not taxed a specific sum, but was entrusted with a particular ritual, which could be performed with greater or lesser magnificence. The chief sphere remained that of civic religion, embodied in the festivals: M.I. Finley notes "in Demosthenes' day there were at least 97 liturgical appointments in Athens for the festivals, rising to 118 in a (quadrennial) Panathenaic year." However groups of rich citizens were assigned to pay for expenses such as civic amenities and even payment of warships. Eventually, under the Roman Empire, such obligations, known as munera, devolved into a competitive and ruinously expensive burden that was avoided when possible. These included a wide range of expenses having to do with civic infrastructure and amenities; and imperial obligations such as highway, bridge and aqueduct repair, supply of various raw materials, bread-baking for troops in transit, just to name a few.
Buddhist liturgy is a formalized service of veneration and worship performed within a Buddhist Sangha community in nearly every traditional denomination and sect in the Buddhist world. It is often done once or more times a day and can vary among the Theravada, Mahayana, and Vajrayana sects.
The liturgy mainly consists of chanting or reciting a sutra or passages from a sutras, a mantra (especially in Vajrayana), and several gathas. Depending on what practice the practitioner wishes to undertake, it can be done at a temple or at home. The liturgy is almost always performed in front of an object or objects of veneration and accompanied by offerings of light, incense, water and food.
Jewish liturgy are the prayer recitations that form part of the observance of Rabbinic Judaism. These prayers, often with instructions and commentary, are found in the siddur, the traditional Jewish prayer book. In general, Jewish men are obligated to pray three times a day within specific time ranges (zmanim). while, according to the Talmud, women are only required to pray once daily, as they are generally exempted from obligations that are time dependent.