Answer:

In rondo form, a principal theme (sometimes called the “refrain”) alternates with one or more contrasting themes, generally called “episodes,” but also occasionally referred to as “digressions” or “couplets

Ternary form, in music, a form consisting of three sections, the third section normally either a literal or a varied repeat of the first.

Binary form is a musical form in 2 related sections, both of which are usually repeated. Binary is also a structure used to choreograph dance. In music this is usually performed as A-A-B-B.