Can You Help me Understand This SATA NVMe PCIe SSD Gen

What happens if I move an NVME with OS on it to another NVME slot? can i use gen 4 nvme in gen 3 slot Yes It's backward compatible It'll work as a device even though it would be capable of working in a slot It will work candy candy slot Best Gen3 SSDs: Samsung 970 PRO and EVO Plus No single drive will take home the crown as the fastest SSD

can i put a gen 4 m2 in a gen 3 slot There seem to be some Gen 4 x4 NVMe 2230 drives in stock at various shops So I have a pair of questions: 1) The HAT is Gen 3 and I read that Gen