What does the X4 mean in an PCIe Gen X4 NVME drive?

Which slot on MSI Z490 motherboard supports PCIe ? m 2 4 0 in 3 0 slot 2 standard contains variants with up to four PCIe lanes, one SATA 6 Gbs and or one USB port So it is possible to connect PCIe as well as SATA SSDs m24 slot wallet Moin Zusammen, mein Board, ein GIGABYTE B550 AORUS Pro V2, bietet im Prinzip drei M2 Steckmöglichkeiten

m2 pcie 40 in 30 slot I don't see a problem with the first 2 cards, but I'm wondering if the 3rd card will work as well? Given that PCIE is twice the bandwidth of