No, they are different; M.2 supports both SATA and PCIe storage interface options, while mSATA is SATA only. Physically, they look different and cannot be plugged into the same system connectors. The picture below shows an M.2 SSD and an mSATA SSD (you can see the connector is different, as are their card sizes):

Module image

M.2 2280 (above) compared to mSATA. Note the Keys (or notches) that will prevent them from being inserted into incompatible sockets.