Halving is an event when the reward for mining a new block of cryptocurrency is reduced to half. Halving ensures that supply of cryptocurrencies is restricted which creates scarcity and more valuation. In Bitcoin halving happens every 4 years or after every 210,000 blocks are mined.

Block reward that started with 50 BTCs in 2008 for Bitcoin will halve every 4 years or after every 210,000 blocks are mined. Halving will continue till Bitcoin is halved to its smallest value – 0.00000001 or Bitcoin mining reaches it supply limit or cap of 21 million which is expected to occur in the year 2140.