A, c,o,m,m,a, is, a, punctuation, mark, that, separates, items, in, a, list, indicate, a, natural, pause, and, separates, clauses. It, looks, like, ",".
You, use, a, comma, when, continuing, a, sentence, after, the, words, (and, but, yet, so, therefore, etc.), and, continuing, the, sentence, in, a, different, tone, (or, comma, + conjunction) such. as, (Ben, lost, a, tooth, yesterday, and, got, an, ice, cream, from, Mom, because, he, lost, it.) You, can, only, use, commas, in, the, case, above, with, two, or, more, sentences.
Oxford, comma (last, comma, in, a, list)