For 10days each year Hindus all over the world celebrate "navratri", literal translation is "9 nights". For 10days people revere and show their gratitude to the feminine energy. People celebrate the female goddess for her power,energy,vitality and generosity.
Myth goes that the demon "Mahishasur" was causing lot of grief to people on the earth. Mahishasur 's temerity reached its pinnacle when he coveted goddess parvati. The goddess was enraged at this amorous demon. She decided to end the miseries of people and kill the demon mahishasur. Goddess Parvati began a wat with the cruel demon but mahishasur was no minion he was incredibly powerful and he fought with treachery and deceit. Goddess fought the demon for 9 days and 9 nights. Finally on the "ashtami" ie on 8th day the goddess manifested herself in to the most powerful entity ever to set foot on earth"mahakali". The dreaded goddess was ruthless and with unprecedented power she waged war with the demon. On the 10th day when the demon was tired and weak Mahakali changed her form into "Mahadurga". Mahadurga is the feminine form of goddess one with sympathy and pity(even for demon who had waged 9days war). She offered truce and gave an offer to spare mahishasur's life. Still the audacity of demon had not subsided he laughed at proposal and continued war, following which on the 10th day Goddess killed the demon with a trident into his chest. People all over the world celebrate this 10th day(Dashami)" as "Vijayadashami or simply Dusshera.
This the the time when people worship the female energy. The energy that can nuture the future generation, the energy that is the cradle of life.
Following is the "Aarti" ie a song of praise to the goddess durga who after killing mahishasur became known as "Mahishasurmardini" ie killer of the mahishasur