What's the bandwidth and form factor for PCIe x1 x4 x8 and x16?

It's a Dell Optiplex 755 Mini Tower The PCIe slot on my PC should be a PCIe slot from what I could find

Gniazdo x1 ma 18 pinów z każdej strony, gniazdo x4 – 32, gniazdo x8

x16 slot 2*PCIe x1 5 EZ-Latch 6 Socket AM5 Supports AMD Ryzen Unlock the latch of the PCIe slot easily when remove the graphics card in the PCIe slot

x1 slot Mağaza Pci Express X1 Adaptör Yükseltici Kartı Pcie X1