The primary purpose of using a microcontroller in electronics is to provide embedded control for various devices and applications. Microcontrollers are compact integrated circuits that combine a processor, memory, and input/output peripherals. They are designed to execute specific tasks, making them ideal for applications such as appliances, automotive systems, and robotics. By integrating control logic with physical components, microcontrollers enable greater automation, energy efficiency, and flexibility in device functionality compared to traditional microprocessors.