What is the difference between personification and onomatopia?

Onomatopoeia is the formation of a Word from a sound associated with what is named for example: "Jingle bells, jingle bells...", "Baa baa black sheep have you any wool?", or "Twinkle twinkle little star..."? Whereas alliteration is an occurrence of the same letter or sound at the beginning of adjacent or closely connected Words for example, "She sells sea-shells down by the sea-shore"