Bitcoin has an halving event to control inflation and maintain scarcity. The halving event reduces the block reward for mining new bitcoins by half every 210,000 blocks, or approximately every four years. This means that the number of new bitcoins entering circulation decreases over time, making the existing supply of bitcoins more scarce.

Scarcity is one of the key factors that drives the price of Bitcoin. When there is a limited supply of something and high demand, the price tends to go up. The halving event is designed to ensure that Bitcoin remains scarce and valuable over the long term.

In addition to controlling inflation and maintaining scarcity, the halving event also serves to incentivize miners to continue mining Bitcoin. Miners are rewarded with bitcoins for verifying transactions and adding new blocks to blockchain. The halving event reduces the block reward, but it also increases the scarcity of bitcoins, which can lead to higher prices. This means that miners can still earn a profit, even if the block reward is lower.