Microcontrollers are small computing devices that contain a processor core, memory, and programmable input/output peripherals. They are designed for specific tasks in embedded systems, such as controlling motors, managing data, and interfacing with sensors and actuators. Microcontrollers are integral to various applications ranging from simple household devices to complex industrial machines and connected systems in the IoT environment. They provide low power consumption and real-time performance, making them suitable for innovative technologies including robotics, automation, and smart devices.