What are the top uses of PCIe x1 Slots?

What are the top uses of PCIe x1 Slots? pcie slot dimensions 4 x PCI Slot : signal via golden finger 3 x : 1 x A Key 1 x B Key w SIM holder (with PCIe pcie 4 in pcie 3 slot PCIe network cards are designed to fit into larger slots , but they cannot fit into smaller slots; for instance, an x8 card

pcie 4 in pcie 3 slot PCIe network cards are designed to fit into larger slots , but they cannot fit into smaller slots; for instance, an x8 card

pcie expansion slot PCIe network cards are designed to fit into larger slots , but they cannot fit into smaller slots; for instance, an x8 card For example, if you connect a PCIe expansion card to a PCIe slot, the card will perform to the PCIe specs PCIe Gen 4 offers