Aarti is a Hindu religious ritual of worship, a part of puja, in which light from wicks soaked in ghee (purified butter) or camphor is offered to deities. Aartis also refer to the songs sung in praise of the deity, when lamps are being offered.
Aarti is said to have descended from the Vedic concept of fire rituals. In the traditional aarti ceremony, flower represents earth (solidity), water represents the water element (liquidity), lamp or candle represents fire (heat), peacock fan conveys the precious quality of air (movement), the yak-tail fan represents the subtle form of ether (space) and incense represents a purified state of mind. Thus with one’s "intelligence" being offered through adherence to rules of timing and order of offerings, one’s entire existence and all facets of material creation are symbolically offered to the Lord via the aarti ceremony.
Aarti is performed during almost all Hindu ceremonies and occasions, involving the circulating of an 'Aarti plate' or 'Aarti lamp' around a person or deity and is generally accompanied by the singing of one of many songs in praise of that deva or person. In doing so, the plate or lamp is supposed to acquire the power of the deity. The priest circulates the plate or lamp to all those present who cup their down-turned hands over the flame and then raise their palms to their forehead - the purificatory blessing, passed from the deva's image to the flame, has now been passed to the devotee. Communal Aarti is performed in the temple; however, devotees also perform it in their homes.
One of the most common aartis is "Om Jai Jagdish Hare".