This document discusses health systems around the world. It defines a health system and describes key metrics for evaluating health systems like life expectancy, infant mortality rate, and access to resources. Developed countries generally have stronger health systems as evidenced by higher rankings on metrics like life expectancy. Barriers to strong health systems in developing countries include lack of funding, resources, and infrastructure as well as issues like corruption and brain drain. The document recommends strategies for improving health systems like increasing funding for primary care, public-private partnerships, and focusing on preventative healthcare and sanitation.