PhD literally stands for Doctor of Philosophy. The initials can also be written as Ph.D. This is the most advanced degree that requires generally 3-8 years of study beyond receiving Bachelor's degree. However, the term PhD is a misnomer. It is not necessary for PhD candidates to study only philosophy as the degree's initial stand for. In fact, many candidates study some other science or different liberal fields related to arts. The title of 'doctor' is also not always used, and in countries like US, it is essentially honorary. Frequently, teachers having degree of PhD are labeled as 'Professor' so as not to get confused with medical doctors.

There are many complementary programs, which involve similar period of studies and take place once a candidate is awarded with the bachelor's degree. These include the Doctor of Education (D.Ed.), Doctor of Medicine (MD), Doctors of Arts (DA) and Doctor of Law (JD). These titles can be earned in place of the PhD degree. Moreover, some of the institutes now offer specialized titles that are equivalent to those given in PhD courses.

PhD work in any subject is quite a challenging task. One must have a clearly defined academic records and should perform well on the GRE - Graduate Record Examinations in both; one's specialty and also in the common test. They must have excellent grades, recommendations and scholastic record of accomplishment in schooling, college and post graduation in order to get into the PhD programs.

In major cases, those pursuing PhD courses in science or liberal arts can spend anywhere from 1-3 years studying advanced levels in their specialized or chosen fields. Usually, time spent on advanced levels tends to be less if one has his or her Master's degree in the same field.

However, some of the programs are so tough that they do not accept the candidates who do not have their Master's degree in the field they want to apply. Others are more likely to accept all the applications from the candidates with only Bachelor's degree but with higher ranks. Therefore, the decision on whom to accept for PhD courses may vary from institute to institute.

Once the course of PhD is completed successfully, candidates are awarded with the degree. Either PhD people may work as professors, lab assistants or they can be employed as research fellows in the field they have mastered. PhD degree holders are generally placed in good and reputed institutes like business schools, medical colleges and other biological research institutes. Any sector, private or government, can recruit PhD fellows. So there is no dearth of lucrative positions for people who have completed their doctorate degrees.

Studies in other countries for doctorate degrees are almost similar to US standards, though slight difference does exist. For instance, most of the European countries offer rigorous courses of study for PhD those are equivalent, or more challenging as compared to US PhD programs. However, most of the countries across the world generally accept the PhD status of those who have their degrees from any reputed and recognized institution, irrespective of country or region.