Diwali, the festival of Light is an important festival of Hindus which is celebrated on Kartika Amavasya day. It is the darkest night of Autumn on Northern Hemisphere and end of month of Kartika. It is the festival after the summer harvest in the Hindu calendar month of Kartika.
Deepavali means row of series of lights. People on that day decorates homes, streets etc., with lamps during the nights and bursts crackers.
As per Skanda Purana Diyas symbolically represent part of Sun the cosmic giver of light energy to all life. Diwali also symbolises the celebration of victory of knowledge over ignorance, good over evil, hope over despair, right over wrong. Hindu philosophy shares the belief that there is something beyond the physical body and mind which is pure, infinite and eternal called Atman, the inner light- the soul. Diwali is the celebration of this inner light over spiritual darkness.
The legends connect Diwali with return of Rama, Laxman and Sita after 14 years of exile and lighting of lamps by the people of Ayodhya to welcome them. It is also believed that this is the day of return of Pandavas after 12 years of Vanavas and one year of Agyanthbas in Mahabharat. It is celebrated as on the night of Diwali Goddess Lakshmi, the Goddess of wealth & prosperity chose Vishnu as her husband. In addition to praying Goddess Lakshmi, the devotees also make offerings to Lord Ganesh, Saraswati and Kuber. Those who pray Lakshmi on this day get blessed with mental, physical and material wellbeing for the year ahead. Hindus in Eastern India like Odisha and West Bengal worship the Goddess Kali instead of Lakshmi and celebrate it as Kali Puja.
The festival is celebrated for 5 days and formally begins two days ahead of the Diwali and lasts two days after that. The first day, the birth day of Lakshmi is celebrated as "DHANTERAS" with shopping day of Gold & Silver. "NARAK CHATURDASI" the day demon Narakas vanquished by Lord Krishna is the second day of festivities celebrated as Choti Diwali. The third day is the Main festive day and celebrated as Lakshmi Puja. Lakshmi is believed to roam the earth on Diwali night. Thus houses are kept open and diyas are lighted to welcome the Goddess and people burst crackers and fireworks to chase away evil spirits. The day after Diwali is celebrated as "Padwa" to celebrate love and mutual devotion between wife and husband through exchange of gifts on this day. Devotees also perform Govardhan Puja in honour of Lord Krishna. The second day after Diwali or the 5th day is celebrated as "Bhai dooj"or "Bhai tika" to mark loving relationship between sister and brother in spirit similar to Raksha Bandhan. On this day sister pray for wellbeing of their brothers.
Jains celebrate festival of light to mark the attainment of Mokshya by Mahavir. Sikhs celebrate Diwali as Bandichhor (day of liberation) to mark release of Guru Hargovind (the sixth Guru) from prison.