Block Chain - Blockchain Architecture Fundamentals

Blockchain architecture explains how digital records are stored and protected across many computers instead of one central database. Every computer in the network keeps the same copy of the information, which strengthens reliability and makes it harder for anyone to secretly change or delete data.

Blocks work like small storage units that hold approved transactions. When a new block is added, it attaches to the previous one, forming a continuous chain. Because each block depends on the block before it, altering old data becomes extremely difficult once many blocks have been added.

Nodes are computers that maintain and verify the blockchain. Each node stores a full history of the ledger and works with other nodes to check new information. The blockchain keeps running smoothly even if some nodes go offline, because many others continue to store and validate the same record.

Consensus mechanisms help all nodes agree on which transactions are valid and what belongs on the chain. Different networks use different rules to achieve agreement, allowing participants to trust the final result without needing a central decision-maker.

Cryptography makes blockchain data secure. A process called hashing converts information into a unique code that changes completely if the data changes even slightly. Since every block contains the hash of the one before it, unwanted edits become obvious immediately, preserving integrity and trust.