Although there are historical differences, there are always some general characteristics. One of these is the instrument of production. The tools used to produce. These are not possible without stored up labor- capital. So capital is another element that is found in all different forms of production.
Production is always a type of production- a certain social body, a social subject.
Marx criticizes the classical economists for being ahistorical about production and making the current capitalist production, and its social relations seem natural. He also notes that distribution and production are often treated separately, and the real relationship between them is not revealed. He also notes that general laws of the relationship between these two dimensions can be discovered. Two preconditions that economists always cite are property and the protection of property. However Marx sees problems with this.