Diwali
Diwali or Deepwali is one of the most important Hindu festivals. The word diwali comes from the Sanskrit word deepwali. The word deepwali can be split in two - “dīpa ” (light) and “āwali” (row or line). So, if literally translated word deepwali means “line of light”.
Diwali is known as the “festival of lights”. The festival represents symbolic victory of good over evil. The lamps lit during this festival celebrate humanity and hope.
The origins of the festival are in the classic Indian epic Ramayana. The festival celebrates the return of Lord Rama after killing Ravana the demon during his 14 years long exile. The day when Ravana was killed is celebrated among Hindu as the holiday called Dussehra. This holiday is celebrated 19 to 21 days before Diwali. In many parts of India there are big fireworks.

Vardhamana (Mahavira)
Diwali is very important for Jains too. Jains are the followers of the Jainism. Jainism has its roots in 24 Jinas ("those who overcome" or conqueror) are believed to exist in ancient East India. The first Jina was a giant who lived 8.4 million years ago. The last Jina was Vardhamana (Mahavira) or "The Great Hero". He was the founder of Jain community. Nowadays majority of about 4 million Jains live in India. Jainism has lot of similarities with Hinduism and Buddhism.
For Jains Diwali represents the start of Jain year. They celebrate Diwali because Lord Mahavira (Vardhamana) achieved Moksha. Moksha or Mukti (from Sanskrit root "muc" - to let loose, let go") means being free from “samsara”, the cycle of death and rebirth or reincarnation and all of the suffering of earthly life.

Guru Har Gobind Ji
Sikhs also celebrate the Diwali. For Sikhs the festival became important since the illumination of the town of Amritsar commemorating the return of Guru Har Gobind Ji (1595-1644), the sixth Guru of Sikhism. He and 53 Hindu kings were imprisoned by Emperor Jahangir at Fort Gwalior. After becoming free again, he went to the Darbar Sahib (Golden Temple) in the holy city of Amritsar. There he was welcomed by the people who lit candles and divas to greet him. That is why today the Diwali is also called Bandi Chhorh Divas or "the day of release of detainees."
Diwali is celebrated for five days which is on 15th day of the dark fortnight in the auspicious Hindu month of Kartik. According to the western calendar it is in October/November. Except the Diwali itself all other days are named according to Hindu calendar.
Dhanteras is the first day of the festival. In its root there is word “Dhan” which means wealth. Dhanteras is also known as Dhantrayodashi or Dhanwantari Triodasi. It Is held on the thirteenth lunar day of Krishna Paksha in the Hindu month of Kartik (October/November).

Goddess Lakshmi
On Dhanteras people worship the Goddess Lakshmi (Laxmi). She is the goddess of wealth, prosperity, light, wisdom, fortune, fertility, generosity and courage. She is also the embodiment of beauty, grace and charm.

Rangoli with lights
To prepare for Dhanteras homes and business buildings are renovated and decorated. Traditional Rangoli designs are made on the entrance of the building to welcome the Goddess Lakshmi. To show that she really arrived people use rice flour and vermilion powder to draw little footprints all over the house. Lamps are kept burning during whole night.
On Dhanteras Hindus buy gold and silver objects or if not possible at least one or two new utensils for the household. People believe that new “Dhan” or some form of precious metal is a sign of good luck.