What Is a “Halving Event” and How Does It Affect the Block Subsidy?

A halving event is a pre-programmed reduction in the block subsidy (the reward for mining a new block) by half. This event occurs approximately every four years on networks like Bitcoin.

Its purpose is to control the inflation rate of the cryptocurrency, ensuring a finite supply and increasing scarcity over time. It directly cuts the fixed portion of a miner's revenue in half, increasing the relative importance of transaction fees.