In the context of blockchain, mining is the process of verifying transactions and adding them to the blockchain ledger. It involves using specialized computer hardware to solve complex mathematical problems that validate the transactions and create new blocks on the chain. Miners compete with each other to solve these problems and the first one to do so receives a reward in the form of cryptocurrency. This process ensures the security and immutability of the blockchain network by making it extremely difficult and expensive to tamper with the ledger.