A Nyquist Plot is a graphical representation used in control theory and signal processing to analyze the stability of a system. It plots the complex frequency response of a system, showing how the output of a system responds to different input frequencies. The plot is created by mapping the real and imaginary parts of the system's transfer function as the frequency varies. The Nyquist Plot helps engineers determine the stability of a control system by examining the encirclements of the critical point (-1, 0) in the complex plane. This analysis is crucial for designing systems that maintain desired performance and avoid oscillations or instability.