Difficulty
Mining & BlocksThis term is part of the Bitcoin glossary — See all terms
Difficulty is how hard it is to find a valid block right now — the network raises it when more miners join so blocks stay ~10 minutes apart.
Bitcoin adjusts a number called the target every 2,016 blocks (about two weeks). If the last adjustment period produced blocks too quickly, difficulty rises; too slowly, it falls. The goal is always the same: one block every 10 minutes on average.
Difficulty matters because it measures how expensive attacks are. Higher difficulty means an attacker needs proportionally more hashrate and electricity to rewrite the chain. It also correlates with miner revenue pressure: when the price of bitcoin rises, more miners pile in, difficulty climbs, and each miner's share of the pie shrinks unless the price keeps up.
