There's no need to boil potatoes before you fry them.
However if you do boil the potatoes before frying the potatoes it gives them a better flavor and more crunchy texture to them.
But there's really no need to boil the potatoes before you fry them and I've never boiled potatoes before I fried them.
I just cut my potatoes up and then place them into the deep fryer or pan to fry them and they've always turned out just fine.
Boil the potatoes if you want too or have time to but it's not a requirement to boil potatoes and is just an extra step that is really not needed.