Karl Marx's class conflict theory is a sociological explanation for how different class structures operate in society. There are two necessities for this model to work. First, there must be a division of labor or access to resources which divides the populace into at least two groups. Secondly, the needs of one class must be of common interest; meaning the group as a whole must have a shared need. When these two situations meet, a conflict will arise because of the disparity between the two classes.
The theory works within contemporary society on many fronts; including economical and cultural conflicts. Economic conflicts are a constant conflict as Marx envisioned. Minimum wage laws in the United States are a source of contention among the lower working class and the investment or ownership class. The economic conflict is the focus of Marx's theory; it also can be applied to cultural issues. The issues of transgendered people in the U.S. are making headlines as they fight as a class to find acceptance in the traditional landscape.
The class conflict theory works well when applied to large groups of people because societies seem to have a need to separate into divisions. Whether economic or cultural, there is conflict among differing groups as they fight for resources.