Doppler Imaging is a technique used in astronomy to study the surfaces of stars. It works by analyzing the light emitted from a star as it rotates. When a star spins, the light from the side moving toward us is shifted to shorter wavelengths (blue shift), while the light from the side moving away is shifted to longer wavelengths (red shift). This shift helps scientists map the star's surface features. By capturing these shifts in light, astronomers can create detailed images of a star's surface temperature and composition. This method has been particularly useful for studying rapidly rotating stars and understanding their magnetic fields and spots.