A motor driver is an electronic device that controls the operation of a motor, allowing it to start, stop, and change direction. It acts as an interface between a microcontroller, like an Arduino, and the motor, providing the necessary voltage and current to drive the motor effectively. Motor drivers are essential in applications where precise control of motor speed and position is required. There are various types of motor drivers, including H-bridge drivers for DC motors and stepper motor drivers for stepper motors. These drivers can handle different power levels and control methods, making them versatile components in robotics, automation, and other electronic projects.