What are PCIe Slots in PC?

Why PCI Express backplanes are so expensiveunpopular? pci 4 in pci 3 slot 4-3, per single PCI Segment Group show less , ECN, November 18, 2018 Errata for the PCI Express® Base Specification Revision , , Errata, October 31 pcie slot function As with previous generations, the standard simply doubles the speed that the PCIe slot runs at It now provides about 2GBs per lane

pcie 4 slot Like USB, PCIe is forward compatible This means that a device which requires PCIe will work in a PCIe or PCIe slot Slot Size Lane Width