Let's see, I think I'll defer to Mr. Keating here from Dead Poet's Society:

We don't read and write poetry because it's cute. We read and write poetry because we are members of the human race. And the human race is filled with passion.And medicine, law, business, engineering - these are noble pursuits and necessary to sustain life. But poetry, beauty, romance, love - these are what we stay alive for.

For me, poetry has always been about putting intense emotion into a particular form.  This is why I absolutely adore writing sonnets.  I love trying to take a particular sensory experience and cramming it into a difficult rhyme scheme, ... I get some kind of masochistic pleasure out of it.

I suspect it wasn't too different from many of our favorite poets as well.  Look at all of the poetic forms we have:  odes, ballads, sonnets, limiricks, ... even songs!!!  It's just another form of literature, ... we can lump it into the group with novels and short stories, ... that is, if you want to take the high school student point of view.  There is no doubt, however, ... poetry contains the most passion.

This is a very difficult question to answer given that you do not offer a little more in what you would like the answer to focus on. Regardless, I will try to answer your question.

Poetry is a form of art which allows a writer to focus on something which, typically, lies heavy on their mind (for good or for bad). Many times, poets use their pieces as an avenue by which they can express their personal feelings about any topic without feeling the constraint of a minimum word count/page count (as with novels) or worry of fitting into a specific genre (not that any authors typically would worry about this).

When I introduce poetry to my students, we listen to music. Surprise!!! Music and poetry go hand in hand. Musicians are simply poets who have set their poems to sound.

As for what poetry "is all about", there is no simple answer to this question. Poetry is about everything and nothing; poetry is about emotions and lack of emotions; poetry is about hardship and success; poetry is about the apples and the oranges.

Poetry, most of it today, is not set to staunch limitations as to how or what a poet can write about. Even when poets did write within the constraints of a Shakespearean or Italian sonnet, it was the poets choice to write in such a fashion.

What is poetry?

United States Supreme Court Justice Potter Stewart famously declined to identified pornography but claimed “I know it when I see it” (Jacobellis v. Ohio, 1964). For most people the same can be said of poetry, that we recognize the generic conventions separating poetry from prose on an intuitive or habitual level.

More rigorously, though, the very concept of poetry should be recognized as something not universal but as a set of historical and culturally determined traditions, which vary across cultures and periods.

Perhaps the earliest distinctions we find among forms of story telling are those in oral-traditional cultures, in which the informal process of conversation is distinguished from the performance of stories that have some sort of cultural or religious significance in clearly delimited settings. These stories which get handed down from person to person and generation to generation develop distinctive literary structures, including repetitions of sounds in recognizable patterns, use of distinctive vocabulary (including retention of older linguistic forms), and typical narrative patterns (quest and return, e.g.)

In the ancient Greek tradition, which was enormously influential on the development of western literature, poetry developed meter, a regular pattern of alternation between long and short syllables, as a distinguishing feature (unlike, for example, Mesopotamian and Hebrew poetry). However, as early as Aristotle, we have a concern that meter alone does not make a poem:

People do, indeed, add the word 'maker' or 'poet' to the name of the meter, and speak of elegiac poets, or epic (that is, hexameter) poets, as if it were not the imitation that makes the poet, but the verse that entitles them all to the name. Even when a treatise on medicine or natural science is brought out in verse, the name of poet is by custom given to the author; and yet Homer and Empedocles have nothing in common but the meter, so that it would be right to call the one poet, the other physicist rather than poet.

While poetry in the western tradition in the period roughly from 1200 BC (or earlier) through the late nineteenth century was generally written in some sort of regular rhythmic form, many more recent forms of western poetry and works from other cultures do not follow this pattern. Instead, the term "poetry" is applied to works that use forms of heightened language, in some way differing from ordinary speech or writing in format (written in lines rather than paragraphs), syntax, or vocabulary.

In trying to define poetry we most be aware that there is no one absolute definition of poetry. The terms is applied to different types of composition over different cultures and periods. In twenty-first century culture, we might say "that's not poetry, it's just doggerel", using the term "poetry" as synonymous for "well-written", while in other cultures or periods people would just have said "that is a bad poem." Also, we tend now to praise good prose by calling it poetic, essential making the term a value judgment rather than a strict analysis of verbal form.

As educators it is important that rather than use the term as a way of imposing our tastes on works we teach, we use it instead to make our students aware of the immense variety of literary materials across different periods and cultural traditions and the different ways people have thought about and characterized those materials.

"Poetry is concentrated word magic."  This definition, from a 1955 student, encapsulates the three most important elements in the definition of our modern word "poetry," which we should not confuse with Aristotle' trifurcation into epic, dramatic, and lyric poetry, by which he was referring to the three modes of fictive verbal communication from one person to another, separated by narratology ("verse," by which he referred to one-narrator -- usually first person -- communication, has now become our word "poetry").  Poetry, then is "concentrated," meaning the author uses a minimum of words to get the point across -- for example, "When I have fears that I may cease to be" -- not "Sometimes, when I am afraid that I will someday die" -- efficient, succinct, economical.  "Word," meaning using language (although to term can be extended by metaphor to mean other arts.  And "magic" meaning that poetry transcends logic or reasoning, but takes advantage of connotation, historical use, and the other ineffable, undefinable traits of language to evoke emotions in the reader/listener. 

There's more to consider about poetry than just its definition.  When we want to write down our thoughts, there are essentially three choices:  list, prose, or poetry.  A list is just that--a series of words which have a fairly loose connection and there is no real attempt to communicate anything with them beyond the obvious.  Prose is anything written in sentence form, ranging from a paragraph to a novel.  In prose, writers can utilize images as well as words to create meaning.  The structure of prose is such that there are rules and conventions to which writers must generally conform.

Poetry, though, is another form of expression entirely.  It uses words and phrases, senses, and imagery--generally in their most condensed, compressed, or compact forms--to create meaning.  All the extraneous elements are omitted, leaving those words and images to draw a picture for the reader.  It may be more or less structured, but it's a condensation of longer and more wordy prose and the effect is generally much more powerful.

Poetry is figurative language in both rhymed and unrhymed forms. It is intended for an audience that enjoys the figurative form that comes from metaphors, similes, and other literary devices. It conveys emotion at all times, as it does not describe factually but, once again, figuratively.

Poetry can come in a diversity of meters and styles, one famous one being a "ballad," which resembles in rhythm the closest thing to a song. The most important thing about poetry is its rich use of metaphors, the appeal to the most nostalgic and sentimental of our senses, and the fact that it has inspired millions since the beginnings of history as a way to express what is real and what is not.