SOME DRS. is an acronym for four different types of doctors: Professors (PROFS), General Practitioners (GPS), Medical Doctors (MDS), and Doctors of Philosophy (PHDS). Professors are typically university faculty members who teach and conduct research in a particular field. General Practitioners are primary care physicians who provide general medical care to patients. Medical Doctors are physicians who diagnose and treat illnesses and injuries. Doctors of Philosophy are individuals who have completed a doctoral degree program in a particular field of study.