Pretty much on the surface for beginners. The good thing: they cover all systems (desktop, mobile) win, mac, android, linux, graphene. I love the way they approach things and they leave it up to the listener to go deeper for himself later on. Verification is clearly advance on not for beginners, and I guess not so much an option on iOS and win anyway. I like the way how the authors try to pitch graphene and linux all the time for better privacy amd security.
