The theory of value plays an essential role in Marx’s analysis. It is at the basis of the explanation of the nature of profit, which is the result of workers’ exploitation, typical of capitalist economies. An important distinction that people find in Marx is the difference between the use value and the exchange value of labour. Human labour has the characteristic of producing a number of commodities whose value is higher than the value of the commodities that are necessary to produce the means of subsistence. An excess arises thus between the use value and the exchange value of labour or, in other terms, between the labour provided by a worker and the labour paid to him, that is, the labour embodied in his subsistence. Capitalism manages this problem by establishing a set of exchange rates, different from values, which are calculated in such a way as to ensure a uniform mark-up proportional to total capital.