NVME M2 drives: which slot to use?

2 slots can take either type of drive It is my understanding that they cannot Is that correct? As a technician, I'm often

Two types of M2 SSD

m2 vs nvme slot 2 standard contains variants with up to four PCIe lanes, one SATA 6 Gbs and or one USB port So it is possible to connect PCIe as well as SATA SSDs

m2 nvme slot 2 SSD cards have two types of connectors, also known as sockets: B key sockets and M key sockets A single card can also have both key types The type of key