The class-in-itself and class-for-itself are concept coined by Karl Marx in his they of class struggle in capitalist society.
Class-in-itself means the objective criteria of any class. This means people sharing the same relationship to the means of production. For example, all laborers have a similar relationship with the landowners. On the other hand, all the landowners as a class have similar relationship with the land and laborers.
Class-for-itself means the subjective criteria of a class. Any collectivity or human grouping with similar relationship would make a category not a class if subjective criteria are not included. It refers to the members of any one class not only have similar consciousness but they also share a similar consciousness of the fact that they belong to the same class. This serves as the basis for uniting its members for organizing social action. Thus, this similar class consciousness towards acting together for their common interest is what Marx calls class-for-itself.
