M.2 is a connector and form factor standard designed for compact expansion modules. Developed as a successor to the mSATA interface, M.2 enables both space-saving designs and high-speed data communication. Today, it is widely used for SSDs as well as Wi-Fi, Bluetooth, LTE, and 5G communication modules.

This article explores the key differences between the two standards, explains the underlying technologies such as QAM modulation, and highlights the design challenges and especially requirements set to connectors and cable harnesses associated with next-generation wireless systems.