The Bitcoin halving is a pre-programmed event that cuts the block reward miners receive by 50%. It occurs every 210,000 blocks — roughly every 4 years.

This mechanism controls Bitcoin's inflation rate. By reducing the rate at which new coins are created, it ensures a predictable, declining supply schedule.

For miners, the halving means earning 50%% fewer coins for the same computational work. Less efficient hardware may become unprofitable. However, halvings have historically preceded significant price appreciation.