Aadhaar number enables targeted delivery through regulated enrolment and a specified residence-period requirement nationwide under law. The Act provides that an Aadhaar number is issued to an individual after enrolment, which requires collecting demographic and biometric information by enrolling agencies as specified by regulations; it also defines resident for enrolment by reference to a minimum period of presence in India preceding the application, tying eligibility for Aadhaar issuance to that residence criterion.