The term "blockchain" in computer science refers to a decentralized digital ledger technology that securely records transactions across multiple computers. Each block in the chain contains a list of transactions and is cryptographically linked to the previous block, ensuring data integrity and transparency. This structure makes it resistant to tampering and fraud, as altering any information would require consensus across the network. Blockchain is best known for its role in supporting cryptocurrencies like Bitcoin, but it extends to various applications, including supply chain management, healthcare, and smart contracts, enabling secure and efficient data sharing.