A rhyme scheme is a pattern of rhyme that repeats throughout a poem.
There are lots of rhyming schemes in poetry.
Structure and examples
Many rhyming schemes deal with rhymes at the end of a line. Here are two of them:
Alternate (or ABAB) rhyme: It rhymes as “ABAB CDCD EFEF GHGH.” So the first and third lines of each stanza rhyme, and the second and fourth lines rhyme.