Video narration
So, is blockchain a currency, a database, or something else? Imagine a shared document where people inspect the same record and its history. Blockchain keeps a common record. But no owner controls the file. New entries are checked by computers on a network. That agreement is called consensus: the network decides which entries count. Accepted records are grouped into a block, and each block points to the previous one, creating a chain. Change an earlier record, and the links stop lining up. The network can spot the inconsistency. That makes the history tamper-evident—not impossible to alter, and not proof that the original information was true. Because copies are maintained across the network, this is called a distributed ledger. Cryptocurrency is one use of blockchain, not its definition. So blockchain is a shared, tamper-evident record: computers agree on entries, group them into blocks, and link those blocks together.