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

What exactly does the spec “PCIe x16 slot ” mean? 1 x pcie 3 0 x16 slot I recently got an LSI 2308, and have not had a chance to test it yet My motherboard only has one PCIE x16 slot , 1_64 slot cars The PCIe x16 Gen3 backplane has two PCI Express x16 slots, with one slot supporting the OSS target adapter card A PCIe x16, x8, x4 or x1 IO PCIe

1_64 slot cars x16 Slot

138 slot online List of Motherboards with 3 PCI-Express x16 Slots: GIGABYTE B650 Gaming X AX V2, MSI X670E Gaming Plus WiFi, ASUS ROG Strix Z790-E Gaming WiFi II, Ever wondered how you can jam a PCIe 16x card like a video card into a PCIe 1x slot? Now you