Health care delivery forms the most visible part of the healthcare system, both to patients and the general public. This sector concentrates on patient flows as well as the organization and delivery of all services dealing with the diagnosis and treatment of disease, or the promotion, maintenance and restoration of health. It covers the main areas of service providers such as public health, primary care, specialized care (often divided into secondary and tertiary care), urgent and emergency care, pharmaceutical care, rehabilitation/intermediate care, long-term care, services for informal carers, palliative care, mental health care, and dental care.