Debit or credit card: Which one is best for student?

<p>Our oldest is looking to buy a house. He just got the copy of his credit report in the mail and he, as a very young 20ish “kid” has an 798 credit score. His only “credit” is his $2500 student loan and his credit card. It makes a HUGE difference having a history too. He has had his card now for several years so that helps as well.</p>