What is Bitcoin? How it works, why only 21 million exist and the risks
Bitcoin is a digital currency that moves directly between users on a public network, with no bank or company in the middle. Miners secure it with computing power, its supply is capped at 21 million coins, and BTC traded near $77,323 as of November 2, 2026.
Bitcoin mining and hashrate explained: difficulty, hashprice and data sources
Bitcoin miners race to find a block hash below a target, and every 2,016 blocks (about two weeks) the network resets the difficulty so blocks keep coming about every 10 minutes. Hashrate, the total guessing power, cannot be measured directly; it is estimated from difficulty and block times.
Bitcoin hashrate is back above 1 zettahash: two difficulty jumps in 13 days
Mining difficulty rose 5.92% on October 16 and another 5.54% on October 29, ending seven months below the 1 ZH/s line. A new record is about 5% away, but miners earn far less per machine than a year ago.