Public health is both a science and an art dedicated to promoting and safeguarding overall well-being, preventing diseases, disabilities, and premature deaths, restoring health when compromised by illness or injury, and enhancing quality of life. It achieves these goals through coordinated efforts and informed decisions made by societies, organizations, communities, and individuals. Public health focuses on population-level interventions to tackle health challenges, including monitoring health trends, addressing disparities, and implementing policies to improve health outcomes. Public health and health promotion are vital components of a society’s efforts to enhance the well-being of its population. They encompass a wide range of activities aimed at disease prevention, fostering healthy behaviors, and creating environments that support health and wellness. Together with primary healthcare, they form the foundation of equitable and sustainable healthcare systems, prioritizing prevention, education, and accessible services to empower communities and improve health outcomes. By addressing social determinants of health, encouraging healthy behaviors, and ensuring equitable access to care, these interconnected disciplines play a pivotal role in reducing health disparities and enhancing quality of life. This chapter examines the essence of public health and its relevance to health promotion and primary healthcare, highlighting their interconnections and emphasizing their collective role in advancing health promotion and preventing illness.