Explanation:

The eclipse of Sun occurs when the Moon comes between Sun and the Earth. The Moon orbits the Earth once a month, and eclipses happen if it lines up exactly with the Earth and the Sun. Solar eclipses occur at New Moon, when  the Moon is between Earth and the Sun. Lunar eclipses occur at Full Moon, when Earth is between the Sun and the Moon. Eclipses do not take place   every month because the orbits of the Moon and Earth are tilted at an angle. Most of the time, the line- up is not precise enough for an eclipse.