NVMe vs vs SATA vs PCIe: What are these SSDs?

Does a nvme gen 4 work in a gen 3 slot? : rbuildapc nvme gen 4 in gen 3 slot The current PCIe Gen 3 slots have started to be replaced with PCIe Gen 4, resulting in double the transfer and bandwidth speed, which means you nvme 40 in 30 slot Gen 4 is faster than Gen 3

nvme vs m2 slot Next Generation Storage：3*PCIe x4 Connectors; Advanced Thermal Ultra-Fast Storage：4* slots, including 3* PCIe x4; Efficient Overall