The term 'blockchain' in technology refers to a decentralized, distributed ledger that records transactions across multiple nodes securely and transparently. Each transaction is grouped into a block, which is then linked to previous blocks, forming a chain. This system provides immutability, ensuring that once a block is added to the chain, it cannot be altered without consensus from the network participants. Blockchain is the foundational technology behind cryptocurrencies, enabling secure peer-to-peer transactions without intermediaries, and has potential applications in various industries, including finance, supply chain, and healthcare.