Poetry is a quality of beauty and intensity of emotion regarded as characteristic of poems: "poetry and fire are nicely balanced in the music".
The words in poems are doing several jobs at the same time. They do one thing with their meaning, and another thing with their sound. Even their meaning may be working on more than one level. An important characteristic of poetry is compression, or concentrated language. I don't mean "concentrated" in the sense of paying close attention. I mean it in the sense of concentrated laundry detergent, or concentrated orange juice. A half-cup of concentrated laundry detergent does the same work as a cup of regular detergent; a poem typically gets across as much meaning as a larger amount of prose. Concentrated orange juice has the water taken out; a good poem has similarly been intensified by removing the non-essential words. This is one reason why poems are often short.