Medicine has historically been considered both a science and an art, and is concerned with the prevention, diagnosis, management and treatment of injury and disease, and the improvement of health outcomes and quality of life for individuals and communities. Some of the cornerstone principals of medicine are the bioethical concepts of non-maleficence (do no harm) and beneficence (provide benefit to the patient). Medical practice seeks to apply medical knowledge, ethical standards and clinical competency to provide the best care for patients. Modern medicine has expanded to incorporate knowledge from the biomedical sciences, genetics, and medical technology, which has impacted and advanced health care, clinical practice and treatment options. Within medicine, there are many specialties /disciplines and subspecialities /subdisciplines, each involving particular knowledge and skills in relation to its practice - with regards to the clinical presentations and types of diseases, organs, and mechanisms involved, its role (diagnostic or therapeutic), the techniques (surgical or non-surgical, scientific/laboratory or clinical) and the technologies (eg. medical imaging) involved in the medical field. Medical practitioners work autonomously and in multidisciplinary teams, in a variety of acute, outpatient, primary care, secondary care, and community healthcare settings across the public, not-for-profit and private sector. A career in medicine is built up over many years. It is a respected and rewarding profession, and often considered a life-long calling. Medicine encourages professional development and the passing down of knowledge to junior medical staff.