What is PCI Express? Do PCIe lanes, slots, and versions matter?

PCIe Gen 4 vs Gen 3 Slots, Speeds pcie 3 slot PCIe x8 Gen expansion backplane with one PCIe slot The PCIe x8 Gen3 backplane supports a PCIe Gen3 target cable adapter installed in the OSS pcie x32 slot 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

pcie 20 x1 slot The specs state that the PCIEX4 and PCI Express x1 slots conform to PCI Express standard In which PCIe slot did you drop the to PCIe x4