Rhyme Pattern
A rhyme pattern is exactly that - the pattern (or occurence) of rhyme in a poem.
Rhymes in poems are assigned a letter, and this corresponds to each occurence of the rhyme.
For example an ABAB rhyme pattern would be:
The grass is green
the sky is blue
I’m supreme
but so are you.
If we assign the letter A to green, then supreme will also be A.
Subsequently blue and you are assigned the letter B.