The history of the festival says that the festival is a festival of lights and joy. The joy in the festival has a specific reason according to the historical support that the festival gets from the oldest epic on the earth, the Ramayana. Rama was the prince of Ayodhya, a province of ancient India and was born to King Dasarath and queen Kousalya. King Dasarath had two other queens also named Kaikayee and Sumitra.
Kaikayee was being motivated negatively to believe that her son Bharat should become king and for that Rama should be sent to the woods. She managed to get that sentence from the king and Rama went to forest, who was assisted by his wife Sita, and his brother, son of Sumitra, Lakshmana. In the woods, Sita was seen by Ravana, the symbolic figure of lust and illusion and he made her captive. Rama had to give a fierce fight with Ravana to make his wife free and win over the lust of the human mind.
Light decoration and meaning
Indians have always considered light as the symbol to dissolute the darkness and they refer that the darkness of the mind is due to the lagging of consciousness and this consciousness is the key to enlighten a mind to understand the life, world and the truth underlying the universe. Ravana is referred to be the symbol of that darkness, who envelops the mind of the human with illusion and wrong thoughts and misunderstandings, and thus the entire world starts running after those illusions and makes himself away from the truth of the world.
Thus the decoration of Diwali becomes prominent with the lights. The light is the symbol to open the windows of the mind to get the darkness of the mind due to the illusion and greed and the false egos goes away with the light of truth. So the light here means the light of the truth and not the light of the discos. The light of consciousness is neither too bright and nor too dark.
The best solution in that case is the light show of the diyas or candle. The light of them are smooth and pleasant. They produces warm which is very insignificant, but the light illuminated is a patient one and also a decent one. The extraordinary lights here in this Diwali festival are not only useless, but are worthless. The soft and patient lights of the diyas makes the entire environment turn into a peaceful situation with the shade of light within the darkness.
Lights are always the symbol of prominence as the makes the entire circumstances and the environment very much clear to the vision of a person. The lights are even beautiful when placed all over the room. The placement of the light is also very much important both from the view of the philosophy and from the view of science.
A proper illumination of the light makes the room enlightened with glory and when the light is of Diya, then the glory seems to be a pious one also. The piousness of the house or the room can thus be maintained with light and thus lighting Diya on the Diwali nights is not only the decoration by lights but also by piousness.