How did Marx's historical materialism explain changes in human societies?

Karl Marx’s theory of historical materialism posits that the economic structure of society—the "mode of production"—is the fundamental driver of historical change. Marx argued that human history is not shaped by ideas or "spirit," but by the material conditions required for survival.1234

Societies are organized around two primary components:
* Material forces of production: The tools, technology, and raw materials used to produce goods.32
* Social relations of production: The division of labor and the social/political arrangements that regulate production.32

According to Marx, the "superstructure" of society—including government, law, and religion—is determined by this economic foundation. Change occurs when the evolving forces of production (such as new technology) come into conflict with existing social relations. When these institutions become "fetters" that inhibit further development, they are eventually replaced through revolutionary upheaval by a new, more advanced economic system. Thus, Marx famously concluded that it is not the consciousness of individuals that determines their existence, but their social existence that determines their consciousness.1234