Bitcoin mining
Bitcoin mining is the process by which bitcoins are released into circulation. Generally, mining requires the solving of computationally difficult puzzles in order to discover a new block, which is added to the blockchain. In contributing to the blockchain, mining adds and verifies transaction records across the network. For adding blocks to the blockchain, miners receive a reward in the form of a few bitcoins; the reward is halved every 210,000 blocks. The block reward was 50 new bitcoins in 2009 and is currently 12.5. As more and more bitcoins are created, the difficulty of the mining process – that is, the amount of computing power involved – increases. The mining difficulty began at 1.0 with Bitcoin's debut back in 2009; at the end of the year, it was only 1.18. As of October 2019, the mining difficulty is over 12 trillion. Once, an ordinary desktop computer sufficed for the mining process; now, to combat the difficulty level, miners must use expensive, complex hardware like Application-Specific Integrated Circuits (ASIC) and more advanced processing units like Graphic Processing Units (GPUs).
These elaborate mining processors are known as "mining rigs."
One bitcoin is divisible to eight decimal places (100 millionths of one bitcoin), and this smallest unit is referred to as a Satoshi. If necessary, and if the participating miners accept the change, Bitcoin could eventually be made divisible to even more decimal places.