Public health nurses comprise the largest professional segment of the workplace in public health and are involved in the prevention, education, advocacy, activism, assessment, and evaluation of Public Health. They hold a vital role in the prevention of disease and help to promote community health and safety. For students already in a nursing program or who are already practicing nurses, public health nursing offers a variety of opportunities to make significant changes in public health. While most nurses care for one patient at a time, public health nurses care for entire populations. The ability to work with whole communities allows public health nurses to help in educating the community about health issues to improve their health and safety and facilitate access to care.