Define 'public health.'

The definition of 'public health' as the science of protecting and improving the health of people and their communities accurately captures the essence of this field. Public health focuses on community-wide efforts to promote health, prevent disease, and ensure access to healthcare resources. It involves a wide range of activities and interventions, including health education, policy advocacy, disease surveillance, epidemiology, and environmental health measures, all aimed at enhancing the overall wellbeing of populations.

In contrast, the other options relate more specifically to healthcare delivery systems or individual patient care. Administering healthcare facilities and managing hospital operations pertain primarily to the organizational and operational aspects of healthcare institutions rather than the broader goals of public health. Individual patient care, while vital, is typically the focus of clinical medicine rather than public health, which seeks to address health determinants affecting entire communities or populations. Thus, the choice correctly highlights public health's comprehensive, community-oriented approach.