mSATA is a type of connection especially found in new generation laptops and desktop computers, which allows mini-SSD solutions to be mounted directly to the mainboard. mSATA has SATA III (6G b/s) speed. mSATA only supports SATA bus. This means it will support a theoretical copying speed of 600 MB per second.
M.2 small form factor is used in many add-on card types such as Wi-Fi, Bluetooth, satellite navigation, Near Field Communication (NFC), digital radio, Wireless Gigabit Alliance (WiGig), Wireless WAN (WWAN) and Solid State Drives (SSD). M.2 is the physical form factor. SATA and PCIe point to the storage interface, which means they use one of these buses.