PCIe vs PCIe : What's the difference?

For years, PCI has been a versatile, functional way to connect sound, video and network cards to a motherboard In addition, a x16 PCIe slot

where pci_address is sys:bus:slot:function How can these two eg 04: Ethernet controller: Realtek Semiconductor Co , Ltd RTL8101E

pcie 4 slot Figure 2 The standard PCI Express slot sizes on computers today are x1, x4, x8, and x16 Software compatibility is also ensured by the PCI

pcie expansion slot A x1 electrical card in any compliant PCIe slot will always run in x1 electrical mode That is, a device designed for Gen-3 PCI Express functions at Gen-2