what is the use of a pan card?

Mentioning of PAN has become mandatory for many financial transactions, particularly in this area like Operating Demat account,Depositing more than 50,000Rs in banks, Investment in mutualfund, Investment,postoffice savings more than 50,000,Sale or purchase of the propety more than 50,000Rs, Signature Proof, Id-proof, You need PAN number to file Income-Tax also By Suriyha Prakyesh