Miners are key players in the network. They provide transaction verification through algorithmic processes to ensure that there is no inconsistency with previous transactions. To do so, they make computing power available (via computer equipment), energy (electricity), premises, staff, etc.
They are rewarded financially by 2 means when they validate a block:
- monetary issue: when a block is mined, 12.5 BTC are generated (2017). Initially, 50 BTCs were generated per block mined, with a division by 2 of the scheduled recompense every 4 years until 2140 (when the issue will become invalid);
- transaction fees: when you make transactions on the Bitcoin network, you must pay transaction fees (FEE). These charges are calculated based on the byte weight of the transaction, not its total in bitcoins. They are collected by miners, and eventually they will be the miners' only remuneration.
Anyone can become a miner and take part in the verification of transactions. It should be noted that this activity is more or less profitable depending on electricity costs.