Redshift refers to the phenomenon where light from distant objects in the universe shifts towards the red end of the spectrum. This occurs due to the expansion of the universe, causing wavelengths of light to stretch as they travel through space. The greater the distance of the object, the more pronounced the redshift, which allows astronomers to determine how far away galaxies and other celestial bodies are. In addition to its role in measuring cosmic distances, redshift is crucial for understanding the universe's expansion and the Big Bang theory. It provides insights into the rate of expansion and the overall structure of the cosmos, making it a fundamental concept in modern astrophysics.