The repetition of a single letter or word

Alliteration - repetition of a letter

Repetition - repetition of a word

Explanation:

Alliteration is a literary device and can be divided into two categories: assonance and consonance

Assonance is the repetition of a single vowel sound within a string of words

Consonance is the repetition of a single consonant sound within a string of words

Repetition is a rhetorical device that utilises the repetition of a single word within a work.

Rhetorical device vs. Literary Device:

Rhetorical devices reflect what the author feels in his or her work, while literary device serve to tell a story.