A microcontroller (MCU) is a compact integrated circuit designed to govern a specific operation in an embedded system. It typically includes a processor, memory, and input/output peripherals on a single chip. MCUs are often referred to as the 'brain' of electronic devices, executing programmed instructions to control hardware functions. They are widely used in applications such as automotive systems, medical devices, home appliances, and IoT devices, where they enable automation and intelligent control. In cybersecurity, MCUs can be both targets and enablers of security, as vulnerabilities in their firmware or communication protocols may be exploited, while secure MCUs can help protect sensitive data and system integrity.