Blockchain consensus refers to the process through which participants in a decentralized network agree on the validity of transactions and the state of the blockchain. This is essential because it prevents double-spending and ensures that everyone has a consistent view of the data.

Different consensus mechanisms exist, with the most common being Proof of Work (PoW) and Proof of Stake (PoS). In PoW, miners compete to solve complex mathematical problems, and the first to solve it gets to add a block to the chain. This process requires significant computational power and energy.

In PoS, validators are chosen to create new blocks based on the number of coins they hold and are willing to “stake” as collateral. This method is generally more energy-efficient and can lead to faster transaction processing. Overall, blockchain consensus helps maintain security, transparency, and trust within the network, enabling it to function without a central authority.