Bitcoin is one of the first digital currencies to use peer-to-peer technology to facilitate instant payments. The independent individuals and companies who own the governing computing power and participate in the bitcoin network—bitcoin "miners"—are in charge of processing the transactions on the blockchain and are motivated by rewards (the release of new bitcoin) and transaction fees paid in bitcoin.
These miners can be thought of as the decentralized authority enforcing the credibility of the bitcoin network. New bitcoin is released to the miners at a fixed, but periodically declining rate. There are only 21 million bitcoin that can be mined in total. As of January 30, 2021, there are approximately 18,614,806 bitcoin in existence and 2,385,193 bitcoin left to be mined.
In this way, bitcoin other cryptocurrencies operate differently from fiat currency; in centralized banking systems, currency is released at a rate matching the growth in goods; this system is intended to maintain price stability. A decentralized system, like bitcoin, sets the release rate ahead of time and according to an algorithm.