Tip - When Should I Use Credit and When Should I Use Debit When Shopping?

Dear Lifehacker, When I'm out shopping, I'm always presented with the option to use debit or credit when I check out. I've heard there are benefits to using credit, but aren't there fees involved that can drive up the price or put a strain on the owner of the shop I'm in? When should I use which? Is there even a difference?
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