Rhyming words have the same ending sounds. Many poems use rhyme, especially at the end of lines. Poetry does not have to rhyme.
Here are some words that rhyme:
Cat, bat, hat, sat, that...
Words that rhyme are not always spelled the same:
No, go, throw, bow, though, stow, yo-yo...
Here are some rhyming words in a poem by Robert Frost:
Whose woods these are I think I know.
His house is in the village though;
He will not see me stopping here
To watch his woods fill up with snow.
Or from L L Cool J:
My radio, believe me, I like it loud
I'm the man with a box that can rock the crowd
Walkin' down the street, to the hardcore beat
While my JVC vibrates the concrete
Here is a link to a rhyming dictionary: Rhyme Zone!