# Glossary & Acronyms

> Glossary of Aadhaar terms and acronyms - UID, EID, VID, URN, POI, POA, POR, CIDR, DBT and more, explained in plain language.

Canonical page: https://eaadhaarinfo.com/glossary

Important: eAadhaar Info is an independent reference publication. It is not UIDAI or a Government of India website. For transactions, current rules and final verification, use the official UIDAI or myAadhaar service linked by the article.

Aadhaar A 12-digit identifier issued by UIDAI after enrolment and de-duplication. It proves identity for supported uses; it is not proof of citizenship or domicile. Aadhaar App UIDAI’s current mobile application for verifiable credentials and selected services, including mobile-number/address update. It is distinct from the older mAadhaar app. Baal Aadhaar Aadhaar enrolled for a child under five without fingerprint/iris capture. The number does not simply expire at age five; missed mandatory biometric updates can cause deactivation. CIDR Central Identities Data Repository—the protected UIDAI repository used for Aadhaar enrolment and authentication. DBT Direct Benefit Transfer: direct electronic delivery of a government benefit. It is broader than Aadhaar Payment Bridge and need not always use APBS. EID Enrolment ID: the 28-digit identifier on an enrolment/update acknowledgement, comprising a 14-digit number and 14-digit date/time stamp. e-KYC Electronic Know Your Customer. Aadhaar-based e-KYC is used only through authorised, consent-based processes. HoF Head of Family: an approved relationship-based route for specified enrolment/address-update situations. MBU Mandatory Biometric Update after ages 5 and 15. It is free in UIDAI’s published windows and must be a stand-alone transaction. Masked Aadhaar A downloadable Aadhaar form that hides the first eight digits and shows only the last four. PoI / PoA / PoR / PDB Proof of Identity / Address / Relationship / Date of Birth. A document counts only for columns marked in UIDAI’s current list. UIDAI Unique Identification Authority of India, the statutory authority responsible for Aadhaar. VID Virtual ID: a revocable 16-digit number that can replace the Aadhaar number in supported authentication/e-KYC transactions.

## Official sources

- [UIDAI homepage (My Aadhaar → About your Aadhaar)](https://uidai.gov.in/en)
- [UIDAI homepage (My Aadhaar → Aadhaar Services)](https://uidai.gov.in/en)
- [UIDAI — current fee sheet](https://uidai.gov.in/en)
- [DBT Bharat](https://dbtbharat.gov.in/static-page-content/spagecont?id=1)

LAST EDITORIAL REVIEW · 26 AUG 2026

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