Originating in southeast Asia, Diwali, also known as the 'festival of lights', is celebrated around the world.
Each year, of Ashvin and Kartika, which typically correspond to October and November.
This year, the main celebrations will start on 29 October and continue for the customary five days.
What does Diwali mean?
The words Diwali or Deepavali mean "a row or series of lights" and festivities include decorating public spaces and homes with lights, fireworks displays, cultural activities and the sharing of food and gifts.
The lights have both mythical and spiritual meaning.
Hindus, Jains, and Sikhs celebrate the spiritual victory of good over evil, light over darkness, and knowledge over ignorance.
Diwali festivities include decorating public spaces and homes with lights, fireworks displays, cultural activities and the sharing of food and gifts. Source: AAP / Tracey Nearmy
What is the Hindu story of Diwali?
A Hindu legend traces the first time the lights were used to tell a story about Lord Rama, who is a descendant of the Hindu god Vishnu.
Rama returns to his kingdom in the ancient Indian city of Ayodhya after 14 years in exile and wins a battle against a demon king.
The story says people lit up their houses to celebrate his victory.
While there are different stories about the festival's origins, even Australians who aren't religious still celebrate Diwali, according to Professor Ian Woolford, a lecturer in Hindi language at La Trobe University.
"In Melbourne ... there are many, many people who are not Indian, and who are not Hindu, who celebrate Diwali now. Perhaps to learn about Indian culture, they see it as a wonderful expression of Indian culture, and perhaps they also think that the message of Diwali is for all people," Woolford said.
"It's significant of the victory of truth over evil, over lies. Victory of light over darkness. This is one thing that it signifies, and of course, perhaps this is become so popular even among non-Indians. This is the message that all of us can appreciate."
In Nepal, the festival is known as Tihar and, along with worshipping Hindu gods and goddesses, animals such as crows, dogs and cows are honoured with gifts of food and adorned with garlands.
The Hindu festival of lights is one of the most important festivals in India. Source: AAP / EPA
"Diwali does have a massive significance behind it. It's not just for fun; just come and enjoy it and walk away with nothing. The light we generate from a diya — it's for enlightening of the self. It's removing all the darkness which is very significant, not just in your home but in your heart as well. So it got a good value, with a good message behind it."
Lights and firecracker displays can also be thought of as an expression of gratitude to the heavens for the attainment of health, wealth, knowledge, peace and prosperity.
Diwali, also known as the 'festival of lights', is a celebration of ancient king Rama's return to his rightful place as ruler of the kingdom of Ayodhya, and represents the victory of light over darkness and good over evil. Source: Getty / Lisa Maree Williams
What happens during Diwali
Day 1: Some traditional activities on the first day of Diwali include spring-cleaning your house, shopping for gold or silver and offering sweets and prayers to the gods.
Day 2: On the second day, some decorate their homes with clay lamps and create rangolis, which are decorative patterns of coloured powder or sand arranged on the floor.
Day 3: The third day of Diwali is considered the festival's main day when people gather to worship the goddess Lakshmi to attain wealth and prosperity.
Day 4: The next day, Nutan Varsh, is celebrated as New Year's Day in the state of Gujarat on India's western coast.
Friends and family exchange gifts and sweets and they also create Annakut — mountains of food arranged in large tiers or shapes representing India's Mount Govardhan.
Day 5: The fifth and last day of Diwali is called Bhai Dooj, which celebrates the love between brothers and sisters. Sisters pray for the health and prosperity of their brothers, and brothers give their sisters gifts.
Some Hindus believe that the goddess of happiness and good fortune, Lakshmi, visits the Earth on this day.
It's thought that if the goddess finds a house that is pure, clean, and bright, she will fulfil the wishes of her devotees.
