What's the difference between noise cancelling and noise isolation headphones?

I'm going on a flight in a few weeks, and want some good [though low budget!] headphones. I'm wondering what's the difference between noise cancelling and noise isolation headphones? Would noise isolation headphones be just as good at disguising aircraft engine noise?What's the difference between noise cancelling and noise isolation headphones?
I think the idea is that noise cancelling uses the way the earphones are constructed to let outside noise in, but in a way such that noise in one ear is 180 degrees out of phase with the other ear. Our brains hear that and cancel the noise out, more or less.





I believe isolation headphones attempt to completely block out any outside noise, physically, ie, completely covering the ear with an insulating substance. Like ear muffs.





Even earbuds can be noise cancelling, but only the big headphones can be truly noise isolation, if I have my terminology correct.





If you want to hear as little as possible from the outside world, you'll want isolation headphones. If you want to be able to hear some things from the outside world, then go with the noise cancelling headphones. That has been my experience, at least. Unless I'm mixing/mastering, I prefer to be able to hear things around me. I sometimes do have to walk around at night due to job hours and whatnot, so I don't wear headphones that will impede my ability to hear the world around me (I also don't play at more than moderate volumes, I always look around me, etc).








Saul