M phase, or mitosis.
(You don't need to know this for your course but more properly cell division could also refer to meiosis or binary fission.)
Another difference would be that DNA contains the 5 carbon sugar deoxyribose while RNA usually contains the 5 carbon sugar of ribose. One differs from the other, as ribose has an additional hydroxyl group bonded to one of the carbon atoms, where as deoxyribose does not.
