A Doctor of Philosophy, commonly known as a PhD, is an advanced academic degree awarded to individuals who have completed extensive research in a specific field of study. This degree typically requires the completion of a dissertation, which is a substantial piece of original research that contributes new knowledge to the discipline. PhD programs are offered in various fields, including the humanities, sciences, and social sciences. Earning a PhD often involves several years of coursework, comprehensive exams, and the successful defense of the dissertation. Graduates with a PhD may pursue careers in academia, research, or specialized professional roles.