Blockchain is a decentralized, distributed ledger technology that securely records transactions across multiple computers in a tamper-resistant and transparent manner. Each block in a blockchain contains a timestamp and links to a previous block, creating a chronological chain of data. This technology is most commonly associated with cryptocurrencies like Bitcoin, but it has applications beyond digital currencies, such as supply chain management, identity verification, and smart contracts. Blockchain has gained attention for its potential to increase transparency, security, and efficiency in various industries.