1/ basics are they burn material away from the lens in layers a bit like digging a shallow hole if its for vision correction. Not sure what they do for cataracts.
2/ a flap is cut with a blade or with the laser then peeled back the work is done then the flap put back in place.
I had LASIK in 1998 to correct myopia (to the tune of -16 diopters). I was and am thrilled by the results (20/20 in one eye, 20/30 in the other). To this day, I have dry eyes, though. Still well worth the tradeoff to me.
Best thing I have ever done. Mine were done in beginning of 2008. Don't do it if you already have dry eyes as it will make it worse. Most good eye docs will not even perform the surgery if you have that condition.