Mining Difficulty

Mining difficulty is the network parameter that sets how hard it is to find a valid block on a proof-of-work chain. The protocol adjusts it automatically — on Bitcoin every 2,016 blocks, roughly every two weeks — so that blocks keep appearing at the intended average interval no matter how much hash rate is connected. When miners add machines and blocks arrive too quickly, the difficulty adjustment raises the target at the next retarget; when hash rate leaves the network, difficulty falls and the remaining miners find blocks more easily. Difficulty therefore tracks competition rather than price, and it explains why buying faster hardware does not permanently increase any miner's share of block rewards.