Bitcoin halving is an event that occurs approximately every four years, or after every 210,000 blocks are mined. During this event, the reward for mining new blocks is cut in half. When Bitcoin was first created, miners earned 50 bitcoins for each block they successfully mined.

This reward was halved to 25 bitcoins in 2012, then to 12.5 in 2016, and finally to 6.25 in 2020. The next halving is expected around 2024, reducing the reward to 3.125 bitcoins. Halving serves two main purposes. First, it helps control the supply of Bitcoin, making it a deflationary asset by limiting the total number that will ever exist to 21 million.

Second, it is intended to create scarcity, which can drive demand and potentially increase the price over time. Halving events are significant for miners and investors alike, as they can influence market dynamics and the overall value of Bitcoin. Historically, halving has often been followed by price increases, though past performance does not guarantee future results.