Cryptocurrency, often referred to as "crypto" for short, is a form of digital or virtual currency that relies on cryptographic techniques for secure transactions and to control the creation of new units. Unlike traditional currencies issued by governments, cryptocurrencies operate on decentralized networks based on blockchain technology. Blockchain is a distributed ledger that records all transactions across a network of computers. Each transaction is verified and added to a block, which is then linked to the previous blocks, forming a chain. This decentralized nature means that no single entity has control over the currency, making cryptocurrencies resistant to censorship and fraud. Cryptocurrencies can be used for various purposes, including online purchases, investment, and remittances. Bitcoin, created in 2009 by an anonymous person or group using the pseudonym Satoshi Nakamoto, was the first and remains the most well-known cryptocurrency. Since then, thousands of other cryptocurrencies, such as Ethereum, Ripple, and Litecoin, have been developed, each with its own unique features and applications.