When the moon passes between earth and sun then solar eclipse takes place. It depends on the position that whether it is obscured totally or partially. It only occurs on the day of new moon. Some mythological stories are related with solar eclipse. In total solar eclipse the sun fully disappears from the sky and darkness prevails for the time being but in partial solar eclipse the sun is slightly darkened by the shadow of eclipse.
During solar eclipse whether it is partial or total the people should not directly look at the sun because during the eclipse the rays of sun are harmful to eyes.

In Hindu mythology there is a story that when nectar was served to God a demon sat among demigods to get the nectar but sun and moon noted his foul trick and reported the matter to Lord Vishnu. Meanwhile that demon drank some nectar and became immortal. From that very day the demon sometimes takes revenge with sun and moon. The head of this demon is known as Rahu and tail is known as Ketu. On the day of solar and lunar eclipse Rahu and Ketu swallow the sun and moon and hence the eclipse takes place.

On the day of solar eclipse people take bath in holy rivers and give grains and food to Brahmins. They recite the sacred Mantras and perform special Pauja to please God.