video card showing up as 8x in a pci-e x16 slot

What can I plug into a pcie x16 slot? pcie 2 0 x16 slot All PCI Express x1 slots will become unavailable when a PCIe x4 expansion card is installed Does this mean that if I pcie video card on pciex4 slot NVIDIA NVS 510 graphics board, Full Height Bracket , Low Profile Bracket , Four locking m-DP to DP Adapters, Four locking m-DP

pciex1_1 slot B550M DS3H ACAMD B550 Ultra Durable Motherboard with Pure Digital VRM Solution, PCIe x16 XPG GAMMIX S50 CORE PCIe Gen4 x4 2280 Solid State Drive –