Miners take bundles of transactions called blocks and attempt to add them to the network. To add them, the block requires a hash, a long number, that depends on all the bits in the block and the hashes of all the blocks that came before it (this ensures a consistent ledger of coins for all accounts across time). Finding this hash is computationally difficult, essentially plugging in numbers and checking over and over again till the right hash is found. The first miner that finds it broadcasts it to all the others. Generating the hash also gives the miner 10 bitcoins. The other miners then add the signed block to their own chain, and begin again on a new set of transactions. Mining gets easier or harder by all miners agreeing to a fixed number of 0s allowed in the hash (think if an 80 digit number has twenty 0s at the end, you have fewer numbers to check than if you didn't know those 20 digits were 0), changing that number every two weeks, dependent on the average time between each block of transactions.
To head off one question, the miner who finds the hash for the block adds new bitcoin for themselves (the reward) with a special transaction type that has no origin address, so it comes out of thin air. Then all the other miners, being honest, agree to respect that creation of new bitcoin when they add the block to their own chain.
Miners take bundles of transactions called blocks and attempt to add them to the network. To add them, the block requires a hash, a long number, that depends on all the bits in the block and the hashes of all the blocks that came before it (this ensures a consistent ledger of coins for all accounts across time). Finding this hash is computationally difficult, essentially plugging in numbers and checking over and over again till the right hash is found. The first miner that finds it broadcasts it to all the others. Generating the hash also gives the miner 10 bitcoins. The other miners then add the signed block to their own chain, and begin again on a new set of transactions. Mining gets easier or harder by all miners agreeing to a fixed number of 0s allowed in the hash (think if an 80 digit number has twenty 0s at the end, you have fewer numbers to check than if you didn't know those 20 digits were 0), changing that number every two weeks, dependent on the average time between each block of transactions.
To head off one question, the miner who finds the hash for the block adds new bitcoin for themselves (the reward) with a special transaction type that has no origin address, so it comes out of thin air. Then all the other miners, being honest, agree to respect that creation of new bitcoin when they add the block to their own chain.