How find out if the PCIe is PCIe or PCIe ?

Can someone explain me the PCI-E slot variations & sizes of pcie slot length I don't think he's concerned about just the full length ports but the half slots that are sprinkled between the full-size slots, those tend to pcie 4 slot PCIe adapters and slots come in 4 different sizes: 1x, 4x, 8x, and 16x Smaller size adapters do fit in larger slots, but larger size adapters do not fit in

pcie slot height 1x PCI-E x16 @ x16 PCIe lanes connected to the slot · 1x PCI-E x16 @ x4 · 2x PCI-E