Doctorate of philosophy

A Doctor of Philosophy (PhD, Ph.D., or DPhil; Latin Philosophiae Doctor) is a type of doctoral degree awarded by universities in many countries. Ph.D.s are awarded for a wide range of programs in the sciences (e.g., biology, chemistry, physics, mathematics, etc.), engineering, and humanities (e.g., history, geography, literature, musicology, etc.), among others. The Ph.D. is a terminal degree in many fields. The completion of a Ph.D. is often a requirement for employment as a university professor, researcher, or scientist in many fields. A clear distinction is made between an "earned doctorate", which is awarded for completion of a course of study and a thesis or dissertation, and an "honorary doctorate", a title granted by a university to a successful or notable person who has not completed doctoral academic work or completed a dissertation at the university. Individuals with an earned doctorate can use the title of "Doctor" with their name and use the post-nominal letters "Ph.D.", "PhD" or "DPhil".

The requirements to earn a Ph.D. degree vary considerably according to the country, institution, and time period, from entry-level research degrees to higher doctorates. A person who attains a doctorate of philosophy is automatically awarded the academic title of doctor. During the studies that lead to the degree, the student is called doctoral student or Ph.D. student, but also doctoral candidate or Ph.D. candidate once the student has completed all of the coursework and comprehensive examinations and is working on their thesis/dissertation (all but dissertation). A student attaining this level may be granted a Candidate of Philosophy degree at some institutions.

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