How is poetry different from other forms of language like everyday speech, fiction, nonfiction, dialogue in a play, and ads on products? what is the purpose of poetry?

I would say that poetry is unique because it deals with truths about the world in a very succinct way ie condensed to capture the meaning of the world of nature and society with a few well chosen words which may or may not rhyme and it also conjures up images quite often and uses metaphors a lot.