Physician in usa with diffrent countries

A physician—also known as doctor of medicine, medical doctor, or simply doctor—practices the ancient profession of medicine, which is concerned with maintaining or restoring human health through the study, diagnosis, and treatment of disease or injury. This properly requires both a detailed knowledge of the academic disciplines (such as anatomy and physiology) underlying diseases and their treatment—the science of medicine—and also a decent competence in its applied practice—the art or craft of medicine.

Both the role of the physician and the meaning of the word itself vary significantly around the world, but as generally understood, the ethics of medicine require that physicians show consideration, compassion and benevolence for their patients.

Life is short, and Art long;
the crisis fleeting; experience perilous, and decision difficult.
The physician must not only be prepared to do what is right himself,
but also to make the patient, the attendants, and externals cooperate.
—First aphorism of Hippocrates, c. 400 BCE, from the Hippocratic Corpus