What is hashrate?
What the hashrate number really measures, why your miner and the pool report slightly different values, and what units to expect.
A measure of mining speed
Hashrate is how much mining work your hardware does per second. The more work, the more chances to contribute to a block, so a higher hashrate means a larger share of the rewards. It is the single most important performance number for a miner.
The units
Hashrate is counted per second and scales up with prefixes: kilo (K), mega (M), giga (G), tera (T) and so on. Different algorithms report in different base units; whatever the unit, a bigger number is more work per second, and the pool shows yours next to the pool and network totals for context.
Why two numbers never match exactly
Your miner console reports its raw local speed; the pool can only estimate your hashrate from the shares it actually receives over a time window. They measure different things, so they are never identical, and the pool figure naturally wobbles with luck over short windows. Compare against the 24-hour average, not the minute-by-minute view.
What lowers your effective hashrate
Stale and rejected shares do not count, so high latency, an unstable overclock or a flaky connection all pull your pool-side hashrate below your card's raw speed. Keeping those low, by choosing a close server and a stable tune, is how you keep your effective hashrate close to your real one.