It is a festival celebrated in Honor of Lord Shiva by the Hindus. Maha Shivratri is an annual festival celebrated on the 13th night and the 14th day of the month of Maagh or Phalguna (both differs in south and North India). It is believed that if you worship Lord Shiva by observing vrat and keeping awake in the night, on this day, which is also considered as the day when Lord Shiva married Goddess Parvati, it would pave way for beneficial changes in your life and wash away the sins you have committed.
What do you do on Shivratri day?
On that day, the devotees take Sankalp to observe fast for the whole day. That evening, the devotees bathe again and perform Shiva Puja at home or visit the temple. Shiva Puja can be performed once or four times at specific intervals during the night. The four time intervals are called the Prahars. You could perform Pujas during the 4 Prahars, either at your home or witness the Pujas performed in the temples and remain awake that night and break the fast. The third Prahar is when Lord Shiva appeared on Earth in the form of Linga and is considered the most important period of the Puja.