Cosmic redshift is a phenomenon in astronomy and astrophysics caused by the expansion of the universe. It refers to the increase in the wavelength of light or electromagnetic radiation from objects in space as they move away from an observer. This shift is observed as a change in the color of the light toward the red end of the electromagnetic spectrum, hence the term “redshift.” The concept of cosmic redshift is closely associated with Hubble’s Law, which states that galaxies are receding from one another, and the recessional velocity of a galaxy is proportional to its distance from the observer. In other words, the farther a galaxy is from us, the greater its redshift.