What is the Aadhar card? Aadhaar is an individual identification number issued by the Unique Identification Authority of India (UIDAI) on behalf of the Government of India to individuals for the purpose of establishing the unique identity of every single person. ... The Aadhar number will serve as a proof of identity and address anywhere in India. What is the Aadhar card? Aadhaar is a 12-digit unique identification number issued by the Indian government to every individual resident of India. The Unique Identification Authority of India (UDAI), which functions under the Planning Commission of India, is responsible for managing Aadhaar numbers and Aadhaar identification cards.