The Bedford Glossary of Critical and Literary Terms - Ross Murfin 2018
Prose: From the Latin for “straightforward,” ordinary written or spoken expression; as applied specifically to literature, nonpoetic expression, that is, expression that exhibits purposeful grammatical (including syntactic) design but that is not characterized by deliberate or regular rhythmic or metrical patterns. Major prose forms include nonfictional works such as biographies and essays and fictional works such as novels and short stories.
The development of prose has generally followed that of verse. Pioneers of English prose include the ninth-century king Alfred the Great, who translated several Latin works, and fourteenth-century theologian John Wycliffe, who undertook the first complete translation of the Bible into English (c. 1380—82). Poets tend to innovate; prose writers, by contrast, tend to imitate, making belated use of those poetic innovations that can be adapted to the prose environment. The more “artful” or “literary” the work of prose, the more it tends to employ poetic devices, such as rhythm, imagery, and sonority (achieved through alliteration, assonance, consonance, etc.). Some creative prose writers adopt traditional poetic devices to such an extent that the line between prose and poetry becomes blurred, hence the designation prose poem.
See poetry for discussion of some differences between prose and poetry.