Bitcoin halving is an event that occurs approximately every four years in the Bitcoin network. During a halving event, the reward that miners receive for validating and confirming transactions on the Bitcoin blockchain is cut in half. This process is programmed into the Bitcoin protocol and is designed to occur every 210,000 blocks, which roughly translates to every four years, until the maximum supply of 21 million bitcoins is reached.
The purpose of the Bitcoin halving is to control the rate at which new bitcoins are created and introduced into circulation. By reducing the rate of new supply, halving events contribute to Bitcoin's deflationary monetary policy, making it increasingly scarce over time. This scarcity is often cited as a key factor driving the value of Bitcoin.
The most recent Bitcoin halving took place on May 11, 2020, when the block reward was reduced from 12.5 bitcoins per block to 6.25 bitcoins per block. This marked the third halving in Bitcoin's history, with previous halving events occurring in 2012 and 2016. Each halving reduces the rate of new bitcoin issuance, making it more challenging and resource-intensive for miners to obtain new bitcoins.