What is meant by consensus in blockchain?

Consensus in blockchain refers to the process by which participants in a distributed network agree on the validity of transactions. This is critical for maintaining the integrity and security of the blockchain. The collaborative nature of blockchain means that no single entity has control; instead, all participants must reach a majority agreement on what constitutes valid transactions. This agreement is achieved through various consensus mechanisms like Proof of Work or Proof of Stake, which ensure that the network can resolve discrepancies and maintain a single version of the truth.

This consensus process ensures that all participants have a synchronized view of the blockchain, which prevents issues such as double-spending and fraud. It is the backbone of the decentralized nature of blockchain technology, allowing it to operate without a central authority. In contrast to the other options, which focus on different aspects of the blockchain network, the concept of consensus is foundational for transaction validation and network security.