A block is a fundamental unit in blockchain technology, encapsulating a group of transactions that have been validated and recorded on the blockchain. Each block contains a unique identifier called a cryptographic hash, a timestamp, transaction data, and the hash of the previous block, which links it to the preceding block, forming a continuous chain. This structure ensures the integrity and chronological order of transactions, as any attempt to alter a block would require changing all subsequent blocks, making the blockchain highly secure and tamper-resistant. Blocks are added to the blockchain through a consensus mechanism, such as proof of work or proof of stake, where network participants validate and agree on the transactions. This process ensures that the blockchain remains decentralized and transparent, enabling secure and trustworthy digital record-keeping.
