Another way of saying "whatever". It is often confused with "same thing", but you're really saying "OK, I admit that they're not the same thing, but they're not different enough for me to really care about it."
Often shortened to same diff.
"Same difference" and "same thing" are not the same thing, but hey, same difference.
an oxymoron, used to describe something as being the same as something else. Often used as an excuse for being wrong. Created by Stephanie Graves in the early nineties.