The difference between M.2 SSD connectors (PCIe vs SATA). Why do some M.2 SSD’s have 2 notches?

The difference between M.2 SSD connectors (PCIe vs SATA). Why do some M.2 SSD’s have 2 notches?

, ssd , nvme , gaming , gamer , gamers , pcbuild , pc , usb , wifi , internet , macbook , technology , tech , computers , computer , informatics , hp , apple , ai