If we talk about literature we talk about poetry as well!

But first... where does it come from? 

(ancient Greek: ποιεω (poieo) = I create

Now... a definition! :D

Poetry, literature that evokes a concentrated imaginative awareness of experience or a specific emotional response through language chosen and arranged for its meaning, sound, and rhytm.

Here you may check this information if you want  https://global.britannica.com/art/poetry 

What about a different definition from the most known! Wikipedia. :D 

It is an art form in which human language is used for its aesthetic qualities in addition to, or instead of, its notional and semantic content. It consists largely of oral or literary works in which language is used in a manner that is felt by its user and audience to differ from ordinary prose.

Nice... isn't it?