"Zero based" means that 0 is the starting number instead of 1. In most computer-related stuff, you start counting with 0 (it doesn't mean "nothing", it is simply the first available number). So 0, 1, 2, 3, 4, 5 instead of 1, 2, 3, 4, 5, 6.
Thanks for your easy explanation. Then how can i switch front and back camera using it?
C-7