Which best explains couplets tercets and quatrains?

Couplets, tercets, and quatrains are all poetic forms that consist of a specific number of lines.

*Couplet* - two-line stanza (AB)

*Tercet* - a three-line stanza (ABA, ABC, or ABB)

*Quatrain* - a four-line stanza (AABB, ABAB, ABBA, or ABCB)