Redshift is a phenomenon observed in light from distant objects in the universe, where the light appears to shift toward the red end of the spectrum. This occurs when an object, such as a galaxy or star, is moving away from us. The faster the object moves away, the greater the redshift. This effect is a key piece of evidence for the expansion of the universe. Astronomers use redshift to measure how far away celestial objects are and how quickly they are receding. By analyzing the light spectrum, they can determine the object's velocity and distance, helping to map the structure and evolution of the universe over time.