The Fundamentals of Public Health series provides an introduction to key perspectives and tools of the public health field. By describing essential public health approaches and illustrating their application with concrete examples, the articles in the series aim to help experts in medicine and public health understand one another, exchange ideas freely, and work collaboratively toward improved and sustainable population health. (The articles on this page appear in order of publication, beginning with the most central principles of the study of public health and building from there.)