Primary, secondary, and tertiary levels of care are described. Primary health care (PHC) is the first level of contact with the health system and aims to provide essential care that is universally accessible, affordable, and encourages self-reliance. PHC includes health education, disease prevention and control, nutrition promotion, maternal/child care, immunization, and treatment of common illnesses. Pakistan implements PHC through basic health units and rural health centers. PHC principles emphasize equitable distribution, community participation, and intersectoral coordination using appropriate technologies.