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

M key: These slots have five pins and support SATA, PCIe, and NVMe protocols They are typically used for high-speed SSDs and other

My small Kingston A2000 drive works and boots in either nvme slot The P3 works only in the first slot I've checked

pcie m2 slot NVMe slot definitions ; 4 - Slimline, NVMe x8, –,

pcie 20 x1 slot NVMe slot definitions ; 4 - Slimline, NVMe x8, –,