The Arduino UNO is the main control unit of the Line Following Robot. It is a microcontroller board based on the ATmega328P chip, widely used in robotics and automation projects. It has 14 digital I/O pins, 6 analog inputs, and USB connectivity for easy programming. In this project, Arduino acts as the brain, receiving input signals from IR sensors and making decisions to control the motors accordingly. Its open-source nature, beginner-friendly interface, and large community support make it an ideal choice for learning embedded systems. The UNO ensures smooth operation by processing commands quickly and accurately.