【Form】 ,  【formality】 ,  【ceremony】 ,  【ceremonial】 ,  【rite】 ,  【ritual】 ,  【liturgy】  mean an established or fixed method of procedure especially as enjoined by law, the customs of social intercourse, or the church.

【Form】 is the comprehensive term applicable to a recognized way of doing things in accordance with rule or prescription.

【Form】 often implies show without substance or suggests an outward shell devoid of its life or spirit.

【Formality】 applies to some more or less perfunctory or conventional procedure required. by law, custom, or etiquette. The term often implies endless detail or red tape.

【Ceremony】  is more specific than  【form】 and implies certain outward acts, usually of an impressive or dignified character, associated with some religious, public, or state occasion or, collectively, with a church or a court.  【Ceremony】 also applies to the conventional usages of civility.

【Ceremonial】  (compare  【CEREMONIAL】  ) is occasionally used in place of  【ceremony】 in its concrete applications; more often it is a collective noun applied to an entire system of ceremonies prescribed by a court or a church. The last three terms of this group refer primarily to religious ceremonies and only secondarily to the ceremonies or forms of civil life.

A  【rite】 is the 【form】 prescribed by a church or other organization for conducting one of its ceremonies or, in the case of a church, for administering one of its sacraments, giving not only the words to be uttered but the acts to be performed.

【Ritual】 is, in effect, a collective noun applied either to all the rites that make up an elaborate religious service or to all the rites or all the ceremonies of a particular church, religion, or organization; it is, however, applicable to a 【rite】 when that represents the one 【form】 in use in the specific religion or body.

Consequently, in extended use,  【rite】  and  【ritual】 both refer to the customary or established order of procedure for conducting not only a 【ceremony】 or a series of 【ceremonial】 acts, but all kinds of formalities or forms.

【Liturgy】  applies primarily to the Eucharistic service, especially that of the Orthodox and the Uniate churches (specifically called "Divine  【Liturgy】  " in many of these) and of the Roman Catholic Church (specifically called the "Mass" in the Latin Church).

In the Anglican Communion  【liturgy】  applies to the Book of Common Prayer, the service book of that church. It is applied also to a strictly religious 【rite】 or 【ritual】 , but this is confusing because  【rite】  and  【ritual】  stress the 【form】 to be followed and  【liturgy】  the complete service as followed in a particular church; thus, the Roman  【rite】  is now generally followed in the  【liturgy】 of that branch of the Roman Catholic Church called the Latin Church.