flying to manilla then to cagayan de oro

I'm flying to cagayan de oro and have to switch planes in manila.

My question is do i have to go to another airport when i land to get onto plane to fly to cagayan de oro or is the plane i will fly on in same airport.

i have never flown out of united states so this is all new to me.

i will be buying all my tickets before i fly so won't have to buy ticket just have to board other plane after a 4 hour lay over.