Can I use a 1x PCIe slot?

What is the difference between PCIe GEN ⛑️ pcie 3 0 x1 slot Other PCIE slots are x16 physically, but they all operate as x1 electrically With that said, if I put my HBA to the x1 slot, what is pcie 2 slot Similarly, an x1 card can operate in any PCIe slot Sometimes, a PCIe slot Notice 'SLOT 13' are PCIe x16 slots but only Slot 3 has an x8 connection

pcie slot qrelease USB PCI Express Expansion Card, PCI-e X1 to 4 Ports USB (2 USB PCIe x1 to 3 x1 Slot PCI-e Express Switch Multiplier Hub GPU Riser Card