The process of cryptocurrency mining generates new coins which are required because blockchain entails sufficient cash to be offered to attract new investors. The creation of new coins is designed to be stable, which retains the worth of cryptocurrency somewhat regular. However, the generation of new coins is not intended to go continually as it saturates the market and finally causes depreciation of the currencies.
To keep the price of given cryptocurrency stable, the process of mining new coins stop eventually when they reach preset amount known as mintage cap. It is the highest level and maximum supply of new coins at which no more coins will be generated.
The current theoretical limit of Bitcoin new coins generation is 21 million by 2140. This is an only predetermined figure built into machinery driving the cryptocurrency. The made in the figure can be changed if the majority of investors vote for change. Usually, the creation of new coins figure is planned in such a way that mintage cap not reached for decades.
Usually, most of the cryptocurrencies such as bitcoin, altcoin have mintage cap, but there are some like peercoin which do not have mintage cap.