In order for Bitcoin miners to actually earn bitcoins by verifying transactions, two things must happen. First, they must validate the transaction, which can theoretically be as small as a transaction, but usually worth one megabyte (MB), depending on how much data each transaction stores. Secondly; miners must solve a complex computational math problem, also called "proof of work", to add a transaction block to the blockchain. What they're actually doing is trying to find a 64-digit hexadecimal number called a "hash" that is less than or equal to the target hash value. Basically, a miner's computer emits hashes at different rates: - megahash per second (MH / s), gigahash / second (GH / s) or terahash / second (TH / s) - depending on the unit, until a solution is reached, 64-digit numbers according to all possible predictions. In other words, it's a gamble. The difficulty level of the latest block was over 16 trillion as of August 2020. So the chance of a computer generating hashes below the target is 1 in 16 trillion. In other words, the probability of winning the Powerball lottery with a single lottery ticket is 44,500 times greater than the probability of catching the correct hash (hash) in a single try. Fortunately, the computer systems used in mining have opened up many possibilities of hashes. However, bitcoin mining requires large amounts of energy for advanced computing. In order to keep mining rates stable, the difficulty level is adjusted every 2016 blocks, or roughly every 2 weeks. So, the more miners compete for a solution, the harder the problem becomes. The opposite is also true. If computing power is withdrawn from the network, the difficulty is adjusted downward to facilitate mining.