The National Health Service (NHS) is the umbrella term for the publicly-funded healthcare systems of the United Kingdom (UK). Since 1948 they have been funded out of general taxation. There are four systems, one for each of the four countries of the UK: The NHS in England, NHS Scotland, NHS Wales and Health and Social Care in Northern Ireland. They were established together in 1948 as one of the major social reforms following the Second World War. The founding principles were that services should be comprehensive, universal and free at the point of delivery—a health service based on clinical need, not ability to pay. Each service provides a comprehensive range of health services, free at the point of use for people ordinarily resident in the UK, apart from dental treatment and optical care. In England, NHS patients have to pay prescription charges; some, particularly those receiving state benefits, are exempt.