PCIe x1 x4 cards in x16 slot

a video card using a PCIe x 16 slot is faster than the video port built in on the motherboard true or false?

PCIe PCIe x 16 Slots 7 · 6 · 5 · 4 · 3 · 2 · 1 SSD Slots 5 x EZ-Latch：PCIe Slot with Quick Release Design; Fast Networks：GbE LAN & Wi-Fi

pcie slot pinout if the slot is open like that, you should be good to go if it's not open, you could a) use another riser to adapt the x8 to x16, or b)

pcie slot dimensions x16 slot, pcie x1 slot, pcie x4 slot, pcie x8 slot, which pcie slot to use, does it matter