Here's an example:
> The cat sat on the mat,
> A furry friend, quite fat,
> He purred and licked his paw, that's that.
Notice how all three lines end with "mat", "fat" and "that", making them rhyme.
Rhyming triplets are often used in:
* Children's poetry because they're easy to remember and read aloud.
* Limericks, where the first, second, and fifth lines rhyme.
* Longer poems, as part of a larger structure.
While the rhyme scheme is simple, it can be used to create a variety of effects, from playful to serious.