Poetry is a more compressed and more regularly rhythmic form of statement. A poem differs from prose in several ways. A poem is more perceptive, thoughtful and considerate, with more attention to sounds and connotations. The reader approaches the poem in the anticipation of out-of-ordinary knowledge and pleasure. He assumes that the poet may use certain enjoyable devices not available to prose: rime (rhyme), alliteration, meter, and rhythms. He expects the poet to make greater use of resources of meaning such as figurative language, allusion, symbol and imagery.
From a poet's perspective, poetry is the art of uniting pleasure with truth by calling imagination to the help of reason (Samual Johnson). Poetry is the imaginative expression of strong feeling, usually rhythmical, and the spontaneous overflow of powerful feelings recollected in tranquility (William Wordsworth). "If I read a book and it makes my whole body so cold no fire can ever warm me, I know that it is poetry. If I feel physically as if the top of my head were taken off, I know it is poetry." (William Wordsworth). Poetry is not the assertion that something is true, but the making of that truth more fully real to us (T.S. Eliot).
Poetry is often classified into metrical verse and free verse on the basis of its use (or non-use) of rime (rhyme), alliteration, meter, and rhythms. While metrical (traditional) verse requires the proper use of rime (rhyme), alliteration, meter and rhythms, free verse does not. However, there is no difference between metrical verse and free verse in their demand for figurative language, allusion, symbol and imagery.