as the rare denimhead who thinks levi's is still king, let me offer a couple of thoughts:
raw just means unwashed and unrinsed as purchased. when the denim comes off of the loom it's either made into jeans right away as STF (shrink to fit) or it's sanforized which is a shrink-proofing process. either one can be "raw".
i saw your other post and i should also tell you that the other thing about raw denim is that it has starch in it. this is so the warp yarns survive the process of weaving. the starch comes out in the wash. if you leave it in it will attract dust and sweat etc and actually abrade the fibers and create wear and blowouts. the best way to help prevent this is to wash out the starch before you start wearing denim in earnest.
most levi's denim is STF. if it is pre-washed it doesn't matter shrinkage should be minimized, and the starch should not be present BUT sometimes what they do is add some kind of resin to the rinse so it feels rough and crispy. if you get a pair of jeans by mail or something and it feels very rough and shellacked then it has starch or resin on it or in it. wash it normally and this will come out. your jeans will last longer but a lot of folks don't do this because they prize SICK FADEZZZ. i personally prefer a nice vintage fade that happens with regular washing anyways but to each their own. good luck.