Chandrasekhara is one of the forms of Lord Shiva, in which he is referred to the one wearing moon on his head front. It is being referred in many Slokas, Puranas and Pujas related to Lord Shiva. The term ‘Chandra’ is referred to Moon and ‘Sekhara’ is referred to Lord Shiva.
While there are many stories which narrate Moon God in relation with Lord Shiva and Lord Ganesha, this story forms the base for all these episodes, as this depicts the very association of Moon God with Lord Shiva.
As the story depics, Daksha, who is considered as the Uncle of Lord Shiva, had twenty seven stars as his daughters. All of his daughters were married to Moon God. Despite having these many wives, Moon was particularly attracted to Rohini. Knowing this, all the twenty seven daughters were not happy and protested against Moon. They had complained to Daksha. Daksha, out of his fury, cursed Moon to mislay his luminance day by day. Out of the 16 parts of his luminance, moon started to lose one by one daily. Embarrassed by this situation, moon disappeared into the ocean to hide.
Absence of moonlight has made the several beings run into troublesome situations, pleading Lord Shiva for help, following the advice of Celestial Gods.
Lord Shiva, with all his Grace, saved the moon, when he was with only one part of luminance. And allowed him to grow his luminance for 15 days and then lose his luminance gradually for the next 15 days, abiding to the curse of Daksha. So this made Lord Shiva, to be called as Lord Chandrasekhara.