What is bitcoin halving ?

Bitcoin halving is an event programmed into the Bitcoin protocol that occurs approximately every four years or after every 210,000 blocks are mined. During a halving, the reward that Bitcoin miners receive for validating transactions and adding them to the blockchain is cut in half. This halving mechanism is designed to control the issuance of new bitcoins and ensure that the total supply of Bitcoin remains finite. It's a key feature that contributes to Bitcoin's scarcity and deflationary nature.