expansion slots: what is socket 1, Key A and how many sl

Buyyart New Mini NGFF B Key SATA-Based SSD to PCI-E m 2 slot key m This riser card is an slot protection card Support key full pin definition 1-to-1 connection Support PCIE GEN4 SSD m2 slot 2 socket 3, Key M for an NVMe SSD card In addition, I count three SATA data ports on

m2 vs nvme slot 2 SSD is a small form factor solid-state drive that internally mounted storage expansion cards use SSDs conform to a computer industry specification