What is the difference between PCIe Gen 3 and PCIe Gen 4?

x1 pcie slot   Dan x16pciexp slot

I have an NI PCIe card and I want to know how many bus lanes it uses In my Development PC, I have a few PCIe slots: x1, x4,

PCIe x1: This is the smallest PCIe slot and has a single lane for data communication PCIe x1 slots are often used for less demanding expansion cards, such as PCIe x1 slot can support all types of wireless cards, including the latest Wi-Fi 6 protocol However, a PCIe x1 slot can only support 1 Gigabit

lindenborg slot IP4X-2D1X is a PCI Express x4 to Four PCIe x1 slots docking system  PCIe x1: These are the smallest PCIe slots, used for almost any other cards like average network adapters and USB expansion cards PCIe x4: