Bitcoin, Dogecoin, and Litecoin, among others, are digital currencies based on the POW model. The amount of currency rewards obtained from mining depends on the effective work contributed to mining, which means that the better the performance of the mining machine and the longer the mining time, the more currency rewards will be obtained. The important significance of proof of work lies in: it forces the generation of currency, requiring a certain amount of work and cost, which endows the currency with certain commodity attributes, allowing the invisible hand of the free market to spontaneously adjust the currency supply through the 'price mechanism', ensuring that the currency has a stable value, thereby allowing the currency to gain people's trust.