Many people understand blockchain as “a database of cryptocurrencies,” but the key is not just storing data—it’s enabling a group of participants who don’t trust one another to jointly maintain the same ledger. Transactions are first broadcast; nodes verify signatures and balances, and then a consensus mechanism determines which transactions are written into a block. The new block is linked to the previous one via hashing; tampering with historical records would break the entire subsequent chain and reveal anomalies. Therefore, the core value of blockchain lies in being publicly verifiable, hard to tamper with, and not requiring a single party to keep the ledger. Note: “tamper-resistant” does not mean the content is necessarily correct. Once a transfer is confirmed, it is typically not reversible—users are still responsible for verifying the private key and checking the address.