Primary health centers (PHCs) are the basic structural and functional unit of public health services in rural areas. PHCs provide primary healthcare to populations of 20,000-30,000 people. They act as a referral unit for 6 subcenters and refer more serious cases to community health centers. PHCs have 4-6 beds for patients, diagnostic facilities, and staff including medical officers and nurses. They provide a range of primary healthcare services like maternal and child care, family planning, treatment of common illnesses, and health promotion activities.