More than half of the world's 100 largest economies are corporations, and an increasing proportion of global deaths are caused by exposure to highly processed foods, alcohol, tobacco, and air pollution. This chapter explores the full spectrum of commercial activities that impact human health, starting with the historical perspective and moving to consider the various frameworks that have been developed in the past decade to both harness and address these commercial determinants. Numerous examples are used to illustrate the actions of industry groups to subvert health-focused policies and foster a damaging narrative that solely blames individuals for harmful levels of consumption. Common industry tactics are dissected, and practical rebuttals are presented to tackle ubiquitous arguments. This chapter also redresses the current harm-focused CDOH balance by considering the positive direct and indirect impact that commerce and corporations can exert through their operations, closing with a selection of simple rubrics that can be used to conduct quick but nuanced assessments of individual firms. In sum, this chapter introduces readers to the field of CDOH; covers the core concepts with the attending historical, political, and philosophical background; and provides the tools required to engage in CDOH research and advocacy.