[Oh god, how young is this kid... How do you dumb down genetics.]

Well, those tigers that are different have something called a mutation. Not like the kind you see in superhero cartoons. These mutations just make their fur come out differently when they're babies.

[As for locations... That one was a little tougher.]

I think the largest population of the white ones are probably the Siberian tigers. They're the biggest and live in a really cold place called Siberia. Makes hiding in the snow easier.