The Bitcoin Halving is an event that takes place every 210,000 blocks or approximately every four years. The reward that miners receive for mining a new block is halved. This mechanism is defined in the Bitcoin protocol and reduces the rate at which new Bitcoins are generated.

The Halving is designed to control the inflation of Bitcoin and limit its supply. By halving the reward for mining every four years, the production of new Bitcoins slows down, helping to keep the total supply of Bitcoins limited to 21 million. This process mimics the mining of raw materials, where it becomes increasingly difficult and costly to extract new resources over time.

Historically, the Bitcoin Halving has often led to an increase in the price of Bitcoin, as the shortage of supply, coupled with steady or increasing demand, can increase the price. However, it is important to note that the Bitcoin market is influenced by many factors and price movements are not solely due to halving.

For miners, the Halving means halving their income per block mined. This may lead to consolidation in the mining sector, as only efficient miners can remain profitable. It could also lead to an increase in transaction fees as miners try to compensate for their loss of income.

Theoretically, the Halving could affect the security of the network if many miners stop their activities because mining is no longer profitable. This would reduce the overall computing power (hashrate) of the network. In practice, however, the network has proven to be resilient, as more efficient mining technologies and the adjustment of mining difficulty help to keep the network stable and secure.

The last Bitcoin Halving took place in May 2020. Since Bitcoin Halvings take place approximately every four years, the next Halving is expected to take place in 2024. The exact time depends on the rate at which new blocks are generated, but it is typically expected around the second quarter of the year.