Healthcare is the maintenance or improvement of health with the help of prevention, diagnosis, treatment and prevention, cure of illness injury, and or physical and mental impairments in society. Health care is delivered by health professionals and allied health fields. Medicines, midwifery, nursing, optometry, audiology, psychology, occupational therapy, physical therapy, athletic therapy, athletic training and other health professions are all part of health care. It includes work done in providing primary care, secondary care, tertiary care, as well as public health.

Health care systems are organizations established to meet the health needs of targeted populations. According to the World Health Organization (WHO), a well-functioning health care system requires a financing mechanism, a well-trained and adequately paid workforce , reliable information on which to base decisions and policies, and well maintained health facilities to deliver quality medicines and technologies.

An efficient health care system can contribute to a significant part of a country's economy, development, and industrialization. Health care is conventionally regarded as an important determinant in promoting the general physical and mental health and wellbeing of people around the world. An example of this was the worldwide eradication of smallpox in 1980, declared by the WHO as the first disease in human history to be eliminated by deliberate health care interventions.