Tryynity wrote...
Still lost 
Many poetic styles, like sonnets and limericks, have two major features: rhyme and meter. You know what rhyme is. Meter is the way the first line of a limerick goes bum-BA-da-da BA-da-da BUM. (there ONCE was a LAdy from THRACE, whose CORset grew TOO tight to LACE) It's a pattern of stresses on the words. This is sort of the default definition of "poetry."
Alliterative verse doesn't have to use rhyme, and while it has a meter, it isn't a set and repeatable pattern. Its major feature is that two or more of the stressed syllables on a line start with the same letter. "Peter Piper picked a peck of pickled peppers."
Blank verse, IIRC, has regular meter but no rhyme. I think it may even mean only iambic pentameter, like (insert famous Shakespeare quote here).
Free verse doesn't have a set style. That doesn't mean it doesn't use standard poetic techniques, but it doesn't *have* to. It may depend upon other things like placement of words on the printed page to achieve an effect as well.
If you've seen
a poem
and it didn't rhyme and it didn't flow and you sat there thinking "what the hell"
you may have seen
a poem
in free verse
(Contrary to my little example, there's more to free verse than taking a sentence and chopping it up in awkward places, although I admit I'm not exactly familiar enough with the genre to really say what goes into it.)