Bitcoin block reward halving takes place for Bitcoin miners.

    Miners are rewarded in Bitcoin for every block they mine. As more blocks are mined, the rewards decrease – the reward is halved for every 210,000 blocks mined.

    Bitcoin halving takes place every four years.

    For example, in 2009 the reward was 50 BTC per block, today it is just 12.5 BTC per block.