What exactly does the spec “PCIe x16 slot ” mean?

However, there is usually a cost increase incurred with higher lane counts PCIe Slot Differences Photo from 20050531pci-express-cards

This video explains everything you need to know about PCIe slots, including PCIe slot sizes

pcie 4 in pcie 3 slot The common PCI Express slots we see on motherboards are PCIe x1, PCIe x4, PCIe x8, and PCIe x16 The number that comes after the x letter tell

pcie cem slot PCI Express x16 — Sixteen lanes, largest slot *some slots may not have matching lanes in bandwidth, more on this throughout the article