Doctor of Philosophy, abbreviated Ph.D. In the English-speaking world it has become the most common denomination for a research doctorate and applies to graduates in a wide array of disciplines in the sciences and humanities.

The Doctor of Philosophy, (Ph.D. or PhD) is a degree a person gets from a university by finishing a doctorate program. In many areas of study, the PhD is the highest degree that a person can earn. There are PhD degrees for many different fields, such as PhDs in literature, philosophy, history, science, mathematics, and engineering.

To be admitted to a PhD program, a person usually has to have completed a Master's degree that is related to the PhD degree. For example, a person applying to be admitted to a PhD degree in Theater would normally have to have a Master's degree such as a Master of Arts (MA) degree in Theater, English Literature, or a related area.

The detailed requirements for award of a Ph.D. vary throughout the world, however there are a number of common factors. A candidate must submit a thesis or dissertation consisting of a suitable body of original academic research, which is in principle worthy of publication in a peer-refereed context. In many countries a candidate must defend this work before a panel of expert examiners appointed by the university.

"One of the most often stated requirements of doctoral research is that it should be an original and significant contribution to knowledge in the discipline in which it was conducted"

There is usually a prescribed minimum period of study (two to three years full time) which must take place before submission of the thesis. The candidate may also be required to successfully complete a certain number of additional advanced courses relevant to their area of specialization.

The Ph.D. has become a requirement for a career as a university professor or researcher in many fields. The Ph.D. is the highest required doctoral degree awarded by universities. The term "Doctor" means "Teacher of Teachers" or "Learned Professional." In addition to university setting research/professor positions, many Ph.D. graduates go on to careers in government departments, NGOs, or in the private sector.
For those wishing to pursue an online Ph.D. degree can do so with many options available to choose from. There are many online Ph.D. degree courses available including distance learning Ph.D. degree.