Nobody can really answer that. There are so many opinions on the subject. It used to be a poem was considered a poem when it rhymed, now that apparently isn't true anymore. But this is what I think about it:
I don’t consider myself a poet, but I do write the occasional poem, mainly for my wife. She is my inspiration. I usually write her one for her birthday, Valentine’s Day, Easter, and Christmas. I’ve written probably over 50 so far. When I told her I want to publish them, she said they belong to her and are not mine to publish. And I respect her wish, but sometimes I make an exception and publish one, like the poem I wrote for her this Christmas. Should you be interested in reading it, please go to my personal blog. ( http://www.hergros.blogspot.com/ ) Much of what I wrote there I wrote here, but you’ll also find the poem.
Writing a poem isn’t much different from writing a story. First, of course, I need a theme, but my heart has to be in it also. That’s why writing a poem for my wife is easy. I start with a word or line and go from there. Sometimes I sit and wait for inspiration. If I get stuck, I quit and continue the next day. Something always pops up. I may write different short sentences and see where they take me. I try to rhyme the last word of two successive lines. I’ve written some poems with rhyming the first line with the third line. There are probably many other ways to write a poem. The way I write mine works best for me.
Like I said, I’m not into poems and haven’t done any studies on how to write them. I’m sure there are rules. However, sometimes other writers publish their poems on the forums I visit and I must say, I’ve read some awful stuff. Some so-called poems don’t rhyme at all. The writers just make up a string of words, sometimes unfinished sentences, and give them their own lines. This is an example of what I’ve seen (not exactly something I read. I made this one up, but it is close enough to give you an idea):
Ice, Water, cold
Must go swimming
Cold, cold, cold
Wet and strange
Clouds in the sky
Flowers and rain
Snowflakes in the clouds
Went out into the rain
Saw mud all over the place
Strange, how the sounds make echoes
Everywhere mud and water
Must write a poem about this
Wonderful experience with water
in the can and in the sky
Fell into a puddle
And got wet
Crazy people watch
Must fly to Africa (Huh?)
The mantra of the world rests on my shoulders
And it is my calling to follow it
I’m not kidding, I read similar stuff like that. It doesn’t make any sense and it doesn’t even rhyme. As far as I’m concerned, any idiot can write garbage like that. Oops, I wrote this. What does that make me? An idiot or a poet. I wonder. Wow! This could be the beginning of something big...Maybe I’m a poet after all. Or maybe another Picasso. Oh, right, he was not a poet but a painter. I never understood his paintings either, but people who apparently know what they’re all about pay millions to buy them. Obviously, it takes a different mindset. Anyway, I don’t consider that kind of stuff poetry. Unless...? Hmm. Perhaps I don’t understand this whole thing. Makes me wonder...Something to ponder... Hey, that rhymes. Another poem coming up?
SLAP! Let’s get back to reality.
What I wrote is my own opinion and I don't want to argue with anyone who disagrees with me. If you think you're a poet I guess you are one and that's all that counts.