A rhyme scheme is usually the pattern of end rhymes in a stanza, with each rhyme encoded by a letter of the alphabet, from a onward (ABBA BCCB, for example).
eg.
- Bid me to weep, and I will weep A
- While I have eyes to see; B
- And having none, and yet I will keep A
- A heart to weep for thee. B
Hope it helps!
Have a nice day! :D