Arati -- A = No, Rati = 'Kamana' or desire. The work by which a 'Niskam' (A state of where there is no desire) is known as Arati. In any idol Puja of Hindu we need perfume material, 'Naibedya' - sliced fruits with sweets, etc. , lamp, incense stick and flowers; so in 'Arati', with all the said material, the spiritual essence of 'Pancha Tattya' (Five Elements) - 'Muladhar', 'Sadhisthan', 'Manipur', 'Anahata' and 'Bisudhakhya' (Chakras) exists. A 'Sadhak' by doing Arati with the 'Pancha Tattya' offers each 'Tattya' (Elements) to God, i.e. it dissolute the 'Jiva Tattya' (material elements of embodied soul). At last a 'Sadhaka' achieves a state of 'Atma Ram' (silence at Kuthastha) and resides in 'Paramananda' (Ecstasy).
But the 'Arati' which are done during materialistic Hindu Puja are not actual Arati. Spiritually its inherent meaning is - A Sadhak by doing relentless 'Atma Karma' (Kriya Yoga) dissolute 'Muladhar' into 'Sadhistan', then 'Sadhistan' into 'Manipur', 'Manipur' to 'Anahata', 'Anahata' to 'Bisudhakhya' and at last 'Bisudhakhya' to 'Agya Chakra' to attain 'Atma Ram'.