Block difficulty is a measure of how hard it is to find a new block in a blockchain. It adjusts periodically based on the total computational power of the network and the time it takes to mine new blocks. When more miners join the network and increase the hash rate, the difficulty level rises.

This ensures that new blocks are still added at a consistent rate. Conversely, if miners leave and the hash rate drops, the difficulty decreases to make it easier to find new blocks. This adjustment mechanism is crucial for maintaining the stability of the network. For example, Bitcoin adjusts difficulty approximately every two weeks.

By regulating the mining process, block difficulty helps control the supply of new coins and secures the network against attacks by making it resource-intensive to validate transactions. In summary, block difficulty balances the mining process, ensuring efficiency and security in the network while influencing how fast new blocks are created.