Camphor is burnt to perform Aarti (circular movement or display of the lamp in reverence before the deity or the idol) before the deity. Just as God rotates the sun and the moon around you, you imitate the same and thus offer and move the camphor lamp before God to bring joy to you. This is also to express the prayer that the light of our life should never go astray from God and should always be centered and revolve around God. It is with this deep feeling that you perform aarti. The breathing of Aarti wakes up the Chakras, some say. The smoke from these balls purify the entire atmosphere.
Puja kapoor has a unique place in the Hindu ritual of traditional Pooja or any other festive or customary occasion. It is pure white in colour, and when it is burnt it takes on the hue of agni (fire), and it burns itself out completely, without residue. Lighting camphor before God symbolizes that if we burn our illusion or ego with the fire of true knowledge, we shall merge with the God, leaving no residue.