Unique Identification Authority of India is the body responsible for the generation of Aadhaar card. Aadhaar is not mandatory but it is voluntary. It can be used as a Proof of Identity and as a Proof of Address. Aadhaar number is required to avail benefits of many govt. schemes.
You don’t have to pay to get your aadhaar card generated. It is free of cost. You need one ID proof and Address proof to prove that you are an Indian resident.
One has to visit an enrollment centre for his/her biometric and fingerprints scan.