Definitions of literature have varied over time: it is a "culturally relative definition". In Western Europe prior to the 18th century, literature denoted all books and writing. A more restricted sense of the term emerged during the Romantic period, in which it began to demarcate "imaginative" writing. Contemporary debates over what constitutes literature can be seen as returning to older, more inclusive notions; cultural studies, for instance, takes as its subject of analysis both popular and minority genres, in addition to canonical works.
The value judgment definition of literature considers it to cover exclusively those writings that possess high quality or distinction, forming part of the so-called belles-lettres ('fine writing') tradition. This sort of definition is that used in the Encyclopædia Britannica Eleventh Edition (1910–11) when it classifies literature as "the best expression of the best thought reduced to writing." Problematic in this view is that there is no objective definition of what constitutes "literature": anything can be literature, and anything which is universally regarded as literature has the potential to be excluded, since value judgments can change over time.
The formalist definition is that "literature" foregrounds poetic effects; it is the "literariness" or "poetic" of literature that distinguishes it from ordinary speech or other kinds of writing (e.g., journalism). Jim Meyer considers this a useful characteristic in explaining the use of the term to mean published material in a particular field (e.g., "scientific literature"), as such writing must use language according to particular standards. The problem with the formalist definition is that in order to say that literature deviates from ordinary uses of language, those uses must first be identified; this is difficult because "ordinary language" is an unstable category, differing according to social categories and across history.
Etymologically, the term derives from Latin literatura/litteratura "learning, a writing, grammar," originally "writing formed with letters," from litera/littera "letter". In spite of this, the term has also been applied to spoken or sung texts.
Literary genre is a mode of categorizing literature. A French term for "a literary type or class". However, such classes are subject to change, and have been used in different ways in different periods and traditions.