The Celestial Equator is an imaginary line that divides the sky into the northern and southern celestial hemispheres. It is directly above the Earth's equator and represents the point where the celestial sphere appears to be balanced. This line is essential for astronomers as it helps in locating stars and other celestial objects in the sky. The Celestial Equator is used in conjunction with other celestial coordinates, such as the Celestial Poles and the Ecliptic, to map the positions of stars and planets. It plays a crucial role in understanding the movement of celestial bodies and is a fundamental concept in the field of astronomy.