Anaphora and repetition are both literary devices that involve the repetition of words or phrases, but there is a subtle difference between the two.
Anaphora refers specifically to the repetition of a word or phrase at the beginning of successive clauses or sentences. This technique is often used to create emphasis and to drive home a particular point. An example of anaphora can be found in Martin Luther King Jr.'s famous "I Have a Dream" speech, in which he repeatedly begins phrases with "I have a dream" to emphasize the central theme of his speech.
Repetition, on the other hand, refers to the use of any repeated word or phrase, regardless of its position in a sentence. Repetition can be used for various purposes, such as to create a sense of rhythm, to emphasize a particular idea or feeling, or to create a sense of unity or cohesion in a piece of writing. An example of repetition can be found in William Shakespeare's play Macbeth, in which the three witches repeatedly chant the phrase "Double, double, toil and trouble" to create a sense of foreboding and mystery.
In summary, anaphora is a specific type of repetition that involves the repetition of a word or phrase at the beginning of successive clauses or sentences, while repetition refers to the use of any repeated word or phrase for various purposes.