expansion slots on motherboard
What are PCIe Slots and Their Uses? - Beginners Guide
PCI Express uses physical slots to interconnect the expansion cards to the motherboard. The common PCI Express slots we see on motherboards are PCIe x1, PCIe x4, PCIe x8, and PCIe x16.
PC/104 - Wikipedia
Under the general terms, PCI Express is used for the representation of the expansion slots on the motherboard of your computing device – whether PC or Laptop.
5 Methods on How to Tell If a PCIe Slot is Bad: Step-By-Step
The 'x16' on the expansion slots is the number of PCIe channels on that slot...however the motherboard will also have a maximum number of channels to allocate ...