The celestial equator is an imaginary line projected onto the celestial sphere directly above Earth's equator. It divides the celestial sphere into northern and southern hemispheres and serves as a reference point for measuring celestial coordinates and tracking the apparent motion of celestial objects across the sky. The ecliptic, on the other hand, is the apparent path of the Sun across the sky over the course of a year, as seen from Earth. It is inclined at an angle of approximately 23.5 degrees to the celestial equator and intersects it at two points, the vernal and autumnal equinoxes, marking the beginning of spring and autumn, respectively. The celestial equator and ecliptic are essential reference lines in astronomy, used to define coordinate systems, locate celestial objects, and predict astronomical events such as eclipses and solstices.