Cryptocurrencies are digital or virtual currencies that use cryptography for security. Unlike traditional currencies issued by governments (fiat currencies), cryptocurrencies operate on decentralized networks based on blockchain technology. The most well-known cryptocurrency is Bitcoin, but there are thousands of others, including Ethereum, Litecoin, and Ripple.

The decentralized nature of cryptocurrency networks makes them immune to government interference or manipulation. Transactions made with cryptocurrencies are verified by miners through a process known as consensus, ensuring transparency and security.

Cryptocurrencies offer numerous advantages, including faster, borderless transactions, and lower fees. However, they also come with challenges such as volatility, security risks, and regulatory uncertainty.