Arati (Hindi आरती), also spelled arathi, aarthi (from the Sanskrit term Aradhana) is a Hindu ritual, in which light from wicks soaked in ghee (purified butter) or camphor is offered to one or more deities.
Ancient religions began with the worship of nature and Arati itself can be considered as a worship of fire, although not as elaborate as the Havan or Homa.
The word “Aa” means “towards or to”, and “rati” means “right or virtue” in Sanskrit and hence Arati can be considered as a ritual drawing a person towards light or knowledge.
The Brhadaranyaka Upanishad says
asato ma sadgamaya
tamaso ma jyotirgamaya
mrtyorma amrtam gamaya
Lead me from the unreal to the reality.
Lead me from darkness to light.
Lead me from death to immortality.
On a subtler level, the arati is also symbolic of this dispelling of darkness or tamas (the lower qualities) by light which symbolizes knowledge.
This site has links to the following popular Aratis
Mantraaonline