Question

What figure of speech uses repetition?

Answer 1

Alliteration - same sound which can involve repetition

Answer 2

There are many figures of speech that use repetition:

Rhyme - Repeating sounds at the end of words.

Alliteration - Uses repetition of a specific consonant sound at the beginning of words or syllables.

And many more! But these are basic ones that you might be referring to.