Cryptocurrency refers to digital or virtual currencies that use cryptography for security and operate on decentralized networks based on blockchain technology. Some well-known cryptocurrencies include Bitcoin (BTC), Ethereum (ETH), and Binance Coin (BNB), among others.

Blockchain is a distributed ledger technology that records all transactions across a network of computers, ensuring transparency and security. Each transaction is stored in a block, which is then linked to previous blocks, creating a chain of blocks - hence the term blockchain.

Cryptocurrencies have gained popularity for their potential to provide financial inclusion, secure transactions, and decentralized control. However, they also pose risks such as price volatility, regulatory uncertainty, and security concerns.