Proof of work (PoW) is a consensus algorithm used in many blockchain networks, including Bitcoin. The algorithm is designed to secure the network by requiring participants to perform a significant amount of computational work to validate transactions and create new blocks in the blockchain.
In a proof of work system, nodes on the network compete to solve a complex mathematical problem. The first node to solve the problem and validate a block of transactions is rewarded with newly minted cryptocurrency and transaction fees. The solved block is then added to the existing blockchain and becomes part of the immutable ledger.
The difficulty of the mathematical problem is adjusted regularly to maintain a consistent rate of block creation and ensure that the network is secure against attacks. PoW requires significant amounts of computational power and energy consumption, making it relatively slow and resource-intensive compared to other consensus algorithms. However, it has proven to be a reliable and secure way to maintain the integrity of the blockchain.