Your PC will use both, but you can only use one at once. If you plug your HDMI cable into the motherboard, you'll be using your integrated graphics, and if you plug your HDMI cable into your GPU, you'll be using that. Having both of these will not give any performance increase, though, so if you plan on getting a dedicated GPU anyway, then there's no point in getting the APU, and you should just get the regular Ryzen 3 1200, unless you want the negligible CPU performance gains the 2200g offers.