Blockchain architecture refers to the structure and design of a blockchain system, defining how it operates and maintains its integrity. At its core, it consists of a network of nodes that communicate with each other. Each node holds a copy of the entire blockchain, ensuring transparency and security. The blockchain itself is a series of blocks, each containing a list of transactions.

Once filled, a block is cryptographically linked to the previous one, forming a secure chain. This linking prevents tampering, as altering any block would require changing all subsequent blocks. Consensus mechanisms, such as Proof of Work or Proof of Stake, are critical components.

They determine how transactions are validated and agreed upon by participants in the network, ensuring that everyone has a consistent view of the data. Smart contracts, programmable scripts that execute automatically when conditions are met, can also be part of the architecture.

They enhance the functionality of the blockchain by enabling self-executing agreements without intermediaries. Overall, blockchain architecture provides the foundation for secure, decentralized, and transparent transaction systems.