The term canon derives from the Greek κανών (kanon), meaning "rule", and thence via Latin and Old French into English.
[1] The concept in English usage is very broad: in a general sense it refers to being one (adjectival) or a group (noun) of official, authentic or approved rules or laws, particularly ecclesiastical; or group of official, authentic, or approved literary or artistic works, such as the literature of a particular author, of a particular genre, or a particular group of religious scriptural texts;[2] or similarly, one or a body of rules, principles, or standards accepted as axiomatic and universally binding in a religion, or a field of study or art.
[3] This principle of grouping has led to more specific uses of the word in different contexts, such as the Biblical canon (which a particular religious community regards as authoritative) and thence to literary canons (of a particular "body of literature in a particular language, or from a particular culture, period, genre").
[1] W.C Sayers (1915–1916) established a system of canons of library classification.
[4] S. R. Ranganathan developed a theory of facet analysis, which he presented as a detailed series of 46 canons, 13 postulates and 22 principles.