This document discusses cryptocurrencies and their impact on the world economy and India. It defines cryptocurrencies and different types like Bitcoin, Ethereum, Litecoin, and Monero. It explains how cryptocurrencies are challenging the US dollar's dominance, cutting out middlemen in financial transactions, and enabling new decentralized markets and crowdfunding methods. In India, cryptocurrencies are not officially recognized as currency but their use is growing, though legal status remains unclear. India's demonetization drove some to use cryptocurrencies due to cash shortages.