A poem is defined as a composition written in verse (although verse has been equally used for epic and dramatic fiction). Poems rely heavily on imagery, precise word choice, and metaphor; they may take the form of measures consisting of patterns of stresses (metric feet) or of patterns of different-length syllables (as in classical prosody); and they may or may not utilize rhyme. One cannot readily characterize poetry precisely. Typically though, poetry as a form of literature makes some significant use of the formal properties of the words it uses ” the properties attached to the written or spoken form of the words, rather than to their meaning. Metre depends on syllables and on rhythms of speech; rhyme and alliteration depend on words that have similar pronunciation. Some recent poets, such as E. E. Cummings, made extensive use of words visual form.
Prose consists of writing that does not adhere to any particular formal structures (other than simple grammar); non-poetic writing, perhaps. The term sometimes appears pejoratively, but prosaic writing simply says something without necessarily trying to say it in a beautiful way, or using beautiful words. Prose writing can of course take beautiful form; but less by virtue of the formal features of words (rhymes, alliteration, metre) but rather by style, placement, or inclusion of graphics. But one need not mark the distinction precisely, and perhaps cannot do so. One area of overlap is prose poetry, which attempts to convey using only prose, the aesthetic richness typical of poetry.