How does blockchain work?

Blockchain is a type of distributed ledger technology that securely records data across a network of computers. At its core, a blockchain is a chain of blocks, where each block contains a list of transactions or records. These blocks are linked together in chronological order using cryptographic hashes, which ensures the integrity and immutability of the data. When a new transaction occurs, it is grouped with others into a block. Before this block is added to the chain, network participants (often called miners or validators) verify the transactions through a consensus mechanism, such as Proof of Work or Proof of Stake. Once verified, the block is added to the existing chain, and because each block contains the hash of the previous block, altering any information in a block would require changing all subsequent blocks — an extremely difficult task without controlling the majority of the network. This decentralized and secure structure allows blockchain to operate without a central authority, making it transparent and resistant to tampering. These properties have made blockchain technology popular for cryptocurrencies like Bitcoin, as well as applications in supply chain management, voting systems, and more.