Cortex M is a family of microcontroller architectures developed by ARM Holdings. It is designed for use in embedded systems, such as automotive electronics, industrial automation, and consumer electronics. Cortex M processors are known for their low power consumption, high performance, and small size. They are highly configurable and support a wide range of peripherals and interfaces. A specialized skill in Cortex M programming involves a deep understanding of the architecture, the ability to write low-level embedded code, and expertise in working with various interfacing techniques.