Miner
In short: A miner is a person, or a company, that mines to contribute to a blockchain network. Miners run specialized computers that bundle transactions into…
A miner is a person, or a company, that mines to contribute to a blockchain network. Miners run specialized computers that bundle transactions into blocks and compete to add the next block to a Proof of Work chain.
Why it matters
Miners secure Proof of Work networks such as Bitcoin. To add a block, a miner must find a block hash below a target set by the network, which takes a huge number of attempts. That work makes past blocks expensive to rewrite, and the miner who succeeds earns the block reward plus the fees of the transactions in the block. Many miners combine their computing power in mining pools to receive smaller but steadier payouts.
Example
A miner connects several ASIC machines to a mining pool. The machines hash candidate block headers again and again, and whenever the pool finds a valid block, it shares the reward among its members according to the work each one contributed. The miner's income then depends on its share of the pool's computing power, the network difficulty and the cost of electricity.