The halving event on the Bitcoin Cash blockchain occurs every 4 years or 210,000 blocks.

The current block reward is 6.25 BCH, the next block reward will be 3.125 BCH. This reduces the rate at which Bitcoin Cash is generated. Halving is a periodic phenomenon and is programmed into the Bitcoin Cash code.

Why was this done? Mainstream fiat currencies allow the government or banks to print money, which leads to inflation. In the case of Bitcoin Cash, the total volume will be limited to 21,000,000 BCH. Printing more money leads to inflation.

Without additional money printing, the value of Bitcoin Cash should rise as demand increases (more people start using Bitcoin Cash) and supply decreases or remains unchanged (Bitcoin Cash is no longer "printed").

This makes Bitcoin Cash similar to gold, which has a limited supply and cannot be “printed” or artificially created.