When Bitcoin came into existence in 2009, it introduced a series of terms and concepts to the world. One of them is the issue of Halving or Halving wages. In fact, the Halving issue makes the most noise for the Bitcoin currency itself. But you should be aware that there are other currencies that have the same Halving argument.
What happens in Bitcoin is that from one block number onwards, the salary that the miners received for mining that block changes and it halves, that slows down the bitcoin inflation rate.
For example, if until yesterday you were mining bitcoins, and you were getting 50 bitcoin units per block, from the specified block number onwards, your salary will be halved, number 25. And this issue continues and it is one of the reasons why bitcoin mining will take until 2140. And it is not the case that all bitcoins will be mined in the next few years. As bitcoin moves into the coming years, the growth and mining of its new units decreases.
The important thing about Halving is that Halving is mostly done in currencies whose consensus algorithm is proof of work.