Can somebody explain what a 2 slot and 3 slot GPUs means?

Just by looking at the picture of the board on the linked website, the second slot says PCI 16_2, which would say to me that it's a PCIe 3 x16

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20bet slot even huge GPUs do only need 2 physical pcie slots for their IO even in the rare case of a 3 slot IO bracket https: c

20 slot demo gratis pg 2 Install your GPU directly to the motherboard and start 3 Enter your BIOS, set the PCIE slot from “Auto” to “Gen 3” (Example photo as below, for more