The difference between PCIe x1, x4, x8, x16 and x32

Looking at the PDF manual the board shows 4 slots, a PCIe x16, 2 PCIe x1, and a PCIe x4, but the key to that diagram indicates that the x4

But it's a full-fledged Windows PC with an Intel Alder Lake-N processor, 12GB of LPDDR5-4800 memory, and an 2242 slot for solid state

pcie slot qrelease The PCIe x1 slot is the smallest PCI Express slot and has the lowest throughput compared to larger PCIe slots such as the PCIe x16 slot

pcie x4 in x16 slot function, RAID Setup wizard, operating system installation function, and diagnostic functions PCIe x16 full-height half-length slots, plus 1x OCP slot