Poetry is something that all people have passing acquaintance with. It is hard to define and as such makes people wary. It has almost as many permeations as music. As such each poet tends to have their own favorite.
What do I think of as poetry? That is a hard question because I am still exploring the various forms. That and poetry, like prose, is always on an adventure of exploration. That having been said, I will try to approach this, as halting as my thoughts may be.
First poetry is sonorous. It falls off the tongue with pleasant sound. It isn't always lyric, but it has music-like quality. Lincoln's Gettysberg Address falls in the prose/poetry area, being both.
Second, poetry is compact. Striped down to just the language needed and carefully chosen words give the most punch. A poem may be long, but if done well each line is very tight.
Third, poetry is the grand temple of figures of speech. Alliteration, onomatopoeia, simile, etc. All things that add impact.
Poetry is from the soul. When you read a poem you learn of the person. His philosophy, what drives him, his general outlook on life.
More important is what isn't poetry
First poetry isn't just a voyage into stilted or flowery language. These may be there, but only if they serve a purpose.
Second, poetry isn't form. Form is something that aids in writing memorable lines. It gives the poet a framework to force his concentration when it wanders.
Third, poetry is not necessarily fraught with secondary or hidden meaning. Sometimes I wonder at the meanings people find in my poems. This is not all bad for any writing should stimulate thought.
Forth poetry is not just for especially deep feelings or philosophy. At one time this was in vogue. Now poetry is used to describe even the mundane. Thanks to people like Ogden Nash frivolous and even silly poems abound.
Lastly poets play with words even more than other types of writers.
Now for a poem:
Oh, silliness, we sing thy praise,
you brighten up our gloomy days
you make us giggle, laugh and snort
and sharpen our mind for quick retort
as bright as sunshine rays.
So let us our glasses raise,
a toast to levity's golden haze
and let our very thoughts cavort—
Troubadours tune their lays
in many and varied ways
but the best, I report
are the light-hearted sort
that are hilarious forays—