Exchange rate volatility makes export earnings and the costs of intermediate goods uncertain. When prices cannot react to exchange rate fluctuations, profit margins have to absorb such volatility. A high level of exchange rate uncertainty, therefore, makes profits unpredictable and hence weighs on investment. Exchange rate volatility that gives rise to adjustment costs would persist for a protracted period. Investment decisions are changed in response to short term uncertainty in profitability of firms. This book reviews world and Indian exchange rate system. And it mainly studies Indian Rupee's volatility against 20 world currencies. The study employs two univariate models which are symmetric and asymmetric that capture common stylized facts of exchange rate volatility clustering and leverage effect. The empirical results show that the conditional volatility is an explosive process of Indian Rupee against the 20 World currencies. It is also found that the volatility of Indian Rupee is persistent against major currencies of the world.