A spectroscopic binary is a type of binary star system where two stars orbit each other closely, making them difficult to resolve as separate entities through a telescope. Instead, their presence is detected by analyzing the light they emit. As the stars move in their orbits, their light spectra shift due to the Doppler effect, revealing their velocities and allowing astronomers to infer their existence. These systems are important for studying stellar masses and dynamics. By observing the spectral lines, scientists can determine the composition, temperature, and motion of the stars, contributing to our understanding of stellar evolution and the behavior of celestial objects in systems like the Milky Way.