The main purpose of ogoh-ogoh is a symbol of Bhuta Kala, made ahead of Nyepi Day and paraded around the village abuzz and eventually burned to charred. It is one of many rituals practiced surrounding Nyepi.
According to the scholars and adherents of Balinese Hinduism, the ceremony ngrupuk is symbolizes human consciousness to the greatness of the universe and the circulation period.
The greatness of the Great Bhuana include power (of the universe) and Bhuana Alit (human beings). In view of Tattwa (philosophy), this power can determine at any living being, especially human beings and the whole world towards happiness or destruction. This all depends on the glory of man, as a creature of God’s most precious in keeping himself and the whole world.
The other meaning of ogoh ogoh festival is to neutralize bad energy from the universe, therefore balinese people are expected to be able to celebrate their silent day by 4 brata without bother from any negative thing.
View this beautiful video of the making of the Ogoh-Ogoh in Bali