Concrete labor and abstract labor are two aspects of the same labor to produce goods, not two or two kinds of labor. Abstract labor and concrete labor are inseparable in time and space. The core difference between abstract labor and concrete labor is that concrete labor creates use value and abstract labor creates value.
Specific labor is different in nature and form, which produces different use value, which is determined by the purpose, mode of operation, labor object, means and result of production. Under the condition of commodity production, concrete labor is one aspect of the duality of commodity production labor. In order to survive and develop, any society and human beings must engage in all kinds of specific labor, transform all kinds of special natural substances, produce all kinds of use values and meet all kinds of needs in life and production.
Abstract labor is human labor or commodity production labor, and it is an economic adjustment from general structure to special structure, that is, a special form of social labor adjustment. Abstract labor refers to human labor that has no difference regardless of the specific labor form. There is no qualitative difference in abstract labor, only quantitative difference. Abstract labor is the source of value, but abstract labor is not equal to value, and abstract labor can only form value if it condenses into commodities.