Difficulty

Network difficulty measures how hard it is to find a block right now. It sets a target that a block's hash must fall below. A higher difficulty means a smaller target, so more attempts are needed on average to find one.

The network adjusts difficulty on its own to keep blocks arriving at a steady pace. When mining power joins, blocks come faster, so difficulty rises. When mining power leaves, blocks slow down, so difficulty falls.

Bitcoin is the classic example. It aims for one block every 10 minutes and recalculates difficulty every 2,016 blocks, about two weeks. If those 2,016 blocks took 12 days instead of 14, blocks were arriving too fast, and difficulty rises by about 14 divided by 12, roughly 17 percent. Many newer coins adjust after every block, using an average of recent block times, so they react within minutes.

Difficulty matters because your earnings depend on your hashrate compared with the whole network. If difficulty doubles because others joined, the same rig earns about half as many coins per day. Nothing changed on your side. You simply hold a smaller slice of the total work.

Network difficulty is not the same as share difficulty. The pool gives your miner a much lower target so it can submit shares often and prove its work. The pool may raise or lower that share difficulty to match your speed. That does not change what you earn, because a harder share counts for more.

A common mistake is to read a calculator once and expect that figure forever. Difficulty moves every day on most coins. When you estimate earnings, use the current difficulty and accept that the number will drift as hashrate joins or leaves.

You can see the current network difficulty and hashrate on the pool's stats page, or on a block explorer for the coin.