Usually rhymes, mostly about feelings, can be very long or short, or even one sentence. (Some people use them in "love letters")
Example:
Roses are red
Violets are blue
Nothing else is more sugary sweet than you

FORMS OF POETRY

Haiku- a pattern with 5 syllables in the first line, 7 in the second, and 5 in the third.

Example:
I like to eat cake 5
I like vanilla frosting 7
With lots of candy 5