What are the Differences between Gen4 and Gen3 PCIe SSDs?

Motherboard does not detect ssd NVME PCIe gen 4 ssd in gen 3 slot Kinda odd he spent nearly 4 minutes talking about the difference between Gen 3 and Gen 4 genie nights slot The great thing about a PCIe gen 4 is that it's backwards compatible If you need to upgrade from a PCIe gen 3 to a gen 4, you can get it as a

genius slot I'm trying my first build and I bought a samsung 980 PCIe NVMe SSD which is a PCIe Gen x4, NVMe interface