Cryptocurrencies are created through a process called mining or via initial coin offerings (ICOs), relying primarily on blockchain technology. Mining involves solving complex mathematical problems to validate transactions and add new blocks to the blockchain, while ICOs allow developers to raise funds for new cryptocurrency projects. Blockchain is a decentralized and distributed digital ledger that ensures transparency, security, and immutability of transaction records. This technology is crucial because it underpins the functionality and trustworthiness of cryptocurrencies.