Blockchain

At its core, blockchain is a decentralized digital ledger that records transactions across a network of computers. Unlike traditional databases, where a central authority controls the data, blockchain operates on a peer-to-peer network. This means everyone in the network has access to the same data, which makes the system transparent, secure, and immutable (i.e., it cannot be changed once recorded). Each record in the blockchain is called a block, and these blocks are linked together (hence the term blockchain) in chronological order. Every block contains: A list of transactions A timestamp A cryptographic hash of the previous block This structure makes tampering virtually impossible. If someone tries to alter a block, it would break the chain — and the rest of the network would reject it.