Bitcoin halving is real, let me explain what halving really means.
Bitcoins need to be mined, like gold. Mining is done in regard to blocks, when one block is mined (mining is basically providing processing power for transactions) the miner gets a reward of x btc.
After a certain number of blocks being mined, the reward per block is halved hence the amount of btc mined per block is halved, and hence the supply.

That's the dynamics, hope it clears things up