A Director Identification Number (DIN) is a unique 8-digit identification number assigned to an individual by the Central Government (Ministry of Corporate Affairs) under Section 154 of the Companies Act, 2013, on application in Form DIR-3. Every person who intends to be appointed as a director of a company must obtain a DIN before such appointment; no company may appoint a director without a valid DIN. The DIN tracks the directorship of an individual across all companies and is linked to their KYC details, enabling regulatory oversight and accountability.