SATA SSD vs PCIe SSD - What's the difference?

In this video I discuss the difference between an SSD and a NVME PCI-Ex4 SSD From how

It is possible to expand with up to three NVMe SSDs, with each slot supporting a maximum capacity of 2TB The leftmost slot is PCIe compatible, with a

m2 pcie 40 in 30 slot Similar to the SATA SSD, the NVMe SSD utilizes the same compact form factor but an NVMe PCIe interface for data transfer NVMe SSDs offer

m2 nvme slot 2 SSDs: SATA and NVMe SATA uses an older interface with one designed around hard drives while NVMe is designed for flash memory