Currency convertibility refers to the ability to exchange domestic currency for foreign currency without limit. There are three types: fully convertible where there are no restrictions, partially convertible where some restrictions exist, and non-convertible where no exchanges are allowed. India has full convertibility for current account transactions like trade but partial convertibility for capital account transactions like foreign direct investment. While greater capital account convertibility could bring benefits like risk diversification and foreign investment, it also poses risks like volatility from hot money flows.