First you need to realize that it is not possible to distinguish between Plato and Socrates. Socrates is a character in Plato’s dialogues, and Plato never talks in his own voice. If you are asked what “Plato” thinks (and no prof should ask this) then you are likely expected to explain Socrates’s position. It’s like being asked about the difference between Shakespeare and Hamlet.
Now, as for what each philosopher thinks, Plato has written over 25 dialogues, and Aristotle has written numerous works as well. It is not possible to sum up all their main ideas, since they had a lot to say about ethics, knowledge, beauty, etc. It would be easier to help you if we knew what dialogues/works you are dealing with.
Plato had the notion that knowledge gained through the senses always remains confused and impure, and that the contemplative soul that turns away from the world can acquire “true” knowledge. The soul alone can have knowledge of the Forms, the real essences of things, of which the world we see is but an imperfect copy. One can view Plato as a sort of idealist and a rationalist.
Aristotle placed much more value on knowledge gained from the senses, and would correspondingly better earn the modern label of empiricist, that would eventually develop into the scientific method.
The book Parmenides presents a series of criticisms of the theory of Forms which are widely taken to indicate Plato’s abandonment of the doctrine. Socrates is either absent or a minor figure in the discussion and this suggests that Plato and Socrates may have differed or at the very least some of Plato’s own ideas were starting to surface. If that is the case then that would mean that Plato and Aristotle might have had more similarities than is thought. It is in the later works by Plato that it is believed that his own thought starts to come forth, yet it is still unclear what that thought is as the later works are quite complex.