Durga Puja also referred to as Durgotsava or Sharadotsav is an annual Hindu festival in South Asia that celebrates worship of the Hindu goddess Durga.
It refers to all the six days observed as Mahalaya, Shashthi, Maha Saptami, Maha Ashtami, Maha Navami, and Vijayadashami.
Durga Puja festival is celebrated from the sixth to tenth day of bright lunar fortnight. This period falls in the fortnight corresponding to the festival is called Devi Paksha, “Fortnight of the Goddess”.
Durga Puja festival marks the victory of Goddess Durga over the evil buffalo demon Mahishasura. Thus, Durga Puja festival epitomises the victory of Good over Evil. In Bengal, Durga is worshipped as Durgotinashini, the destroyer of evil and the protector of her devotees.
According to Hindu mythology, Mahishasura was a combination of both an Asura and a Mahisha (Water buffalo) with trident. He intended to annihilate all the Devas since they were the arch-enemies of Asuras. The legend of Mahishasura is important in Hindu mythology since the goddess Durga was born in order to slay him. Therefore, his story is an important part of shaktiism which venerates the goddess Durga.
Rambha, the king of Asuras, was enticed with the beauty of a she-buffalo and eventually married her. The child who was born from this bestial union was named Mahishasura, because he was half-buffalo and half-human (Mahisha literally means buffalo). As an Asura, Mahishasura wanted to wage war against the Devas, who were the Asuras’ arch-enemies. To make himself invincible Mahishasura performed austerities (tapas) to Brahma and asked to be granted immortality. Brahma refused him the boon of immortality and instead gave him a boon such that his death would happen only at the hands of a woman. Mahishasura imagined that this was the equivalent of immortality, since he believed it was impossible for a woman to slay a person of his strength. Emboldened by this belief, he started a war with the Devas. In the battle that ensued, the Devas, led by Indra, were defeated. At this point the Devas approached the trinity of Shiva, Brahma and Vishnu to seek help. The three great gods combined their divine energies and created a woman. The Goddess thus created was Durga. Durga led a battle against Mahishasura and killed him, thus fulfilling the prophecy that he would meet his death at the hands of a woman.
The actual worship of the Goddess Durga as stipulated by the Hindu scriptures falls in the month of Chaitra, which roughly overlaps with March or April and is called Basanti Durga Puja. This ceremony is not observed by many and is restricted to a handful in the state of West Bengal, Assam, Tripura. The more popular form, which is also known as Sharadiya (Autumnal) Durga Puja, is celebrated later in the year with the dates falling either in September or October. Since the Goddess is invoked at the wrong time, it is called “Akaal Bodhon” in Bengali.
There is also a mythological belief that Lord Ram, who was a Durga worshiper, worshiped Goddess Durga before going to war with Ravana. Rama had performed “Chandi Homa” and invoked the blessings of Durga, who blessed Rama with secret knowledge of the way to kill Ravana. On the day of Ashvin Shukla Dashami, Rama’s party found Sita and defeated Ravana. This day is thus also celebrated as Dussehra.