Root Locus is a graphical method used in control system engineering to analyze how the roots of a system's characteristic equation change with varying feedback gain. It helps engineers visualize the stability and performance of a system as they adjust parameters, particularly the gain K. The paths traced by the roots in the complex plane indicate how the system's poles move, providing insights into system behavior. The technique is particularly useful for designing controllers and understanding the effects of feedback on system dynamics. By plotting the root locus, engineers can determine the optimal gain values that ensure desired performance, such as stability and responsiveness, in control systems.