SAS or SATA use the SCSI protocol. The SCSI protocol uses acknowledgment overhead to make sure data is received. The NVMe protocol is much slimmer, has less overhead and uses fewer CPU cycles to process. Therefore, it is much faster than SATA and lower latency.
There are various examples of NVMe technology being used in mobile devices at extremely low power--the most notable being the Apple iPhone. M.2 and NVMe BGA devices for notebooks, laptops, and tablets are also demonstrating lower power and improved battery life vs SATA.
The NVMe specifications use the PCIe interface for low latency and scalable performance. Current PCIe 3.0 x4 NVMe SSDs are 6-7x faster than a SATA SSD, and PCIe 4.0 SSDs are 12-13x faster than a SATA SSD.
NVMe SSDs can me managed in-band (through the operating system) and out-of-band (outside of the host OS, generally through a BMC). Many open source management tools exist to manage NVMe SSDs, like nvme-cli in Linux that contains all the commands in the NVMe specification to monitor device health and endurance, update firmware, secure erase drives, [...]
There are multiple commands in the NVMe specification to securely erase user data. The NVMe format command includes support for crypto erase to quickly erase user data by switching the crypto key, as well as full media erase which today physically erases the NAND. Sanitize is the other command to erase user data. It has [...]
The M.2 specification, defined by PCI-SIG, is a form factor for small devices, such as SSDs and WiFi cards. M.2 supports SATA as well as PCIe technology, but most commonly M.2 SSDs are NVMe SSDs.
The use of PCIe SSD, NVMe SSD, NVMe/PCIe SSD are all common and acceptable. Most people today use NVMe SSD to imply a PCIe SSD (since that is what has existed from 2011 to today) but in the future, NVMe SSDs may also be on other physical interfaces beyond PCIe architecture.