Imagine a digital ledger shared among many computers. This ledger securely records information, like transactions, in "blocks" chained together chronologically. This is a blockchain. It's decentralized, meaning no single entity controls it, and transparent, as everyone on the network can view the information. This technology ensures security and trust, as altering any information requires changing all subsequent blocks across the network, making it extremely difficult to tamper with. Blockchains are used for various applications, notably cryptocurrencies like [[Bitcoin]], but also for supply chain management, voting systems, and more.