Aadhaar Card is card bearing a 12-digit unique Identification number issued by Unique Identification Authority of India (UIDAI) the regulatory body, to individuals who apply to get their Aadhaar number, for the purpose of establishing unique identification.

It is made for individuals of any age for the purpose of establishing identities and it is different for all the members of a family including children. For deciding uniqueness of every individual, the demographic details (details of residential address) of the person and his/her biometric information (photograph, iris-scan, fingerprints) is collected and is stored in a centralized database.

Aadhaar is not compulsory but is voluntary. Any individual interested in having Aadhaar number can apply to get Aadhaar number for himself or members of his family, free of cost. It is valid for the whole life of any individual.

The Aadhaar number can be used while opening a bank account, applying for passport, booking e-tickets and many other places where there is a need to give your identity.

Any resident of India, Non Resident Indian (NRI) or any foreign citizen residing in India can apply for Aadhaar. As it is only for proving uniqueness and not for granting citizenship, even NRIs and foreign citizen residing in India can enjoy the benefits of Aadhaar.

To get an Aadhaar, an individual needs to visit the authorised Aadhaar enrolment centre with certain documents of his/her identity and address proof.

The main steps for getting Aadhaar:

1. Going to any nearby authorised Aadhaar enrolment centre, taking your documents of address and identity proof (original or photocopies attested by a gazetted officer) along with Aadhaar enrolment form.

2. At the enrolment centre, going through the document verification process.

3. After giving details, taking of fingerprint and iris scanning.

4. After that photograph of that individual will be taken.

A printed acknowledgement slip with an enrolment number and other details will be given to the applicant.

Details will then be verified and after verification, a unique Aadhaar number will be generated which will be dispatched to the individual’s address after a few days or weeks, in the form of Aadhar Card.

http://uidai.gov.in/aadhaar.html