installing Gen4 NVME on a Gen3 Motherboard

What does the X4 mean in an PCIe Gen X4 NVME drive? can i use gen 4 ssd on gen 3 slot PCIe Gen 3 and Gen 4 adapter choices with support for Gen 5 adapters when available OCP slot with PCIe Gen 4 x16 interface candy clash slot use cases focusing on NVMe SSDs and GPU 2 X16 GEN 4 CARD for 4 Nvme but it's OK for only one slot I should change to x4x4x4x4

cancel tesco delivery slot On my Asus x570 C8H, I can set each PCIe slot, each slot and the south bridge link to either Gen 3 or Gen 4 independently I'm currently