The PhD is a doctoral degree, specifically called a "doctor of philosophy" degree. This is misleading because PhD holders are not necessarily philosophers (unless they earned their degree in philosophy!). That said, PhD recipients are able to engage in thought experiments, reason about problems, and solve problems in sophisticated ways.
What Can You Earn a PhD in?
The PhD is awarded in all disciplines.
What Does Earning a PhD Entail?
Like a master's degree, the doctorate also entails coursework. PhD degrees also require that students pass comprehensive exams and a large scholarly project called a dissertation. The completion of the dissertation signifies that the student is able to make significant independent contributions to the field.
How Long Does it Take to Earn a PhD?
Typically it requires several years of study beyond the master's degree. The exact number of years varies by discipline and by student. Some students complete in 4 years and others take up to 8 or more years of study depending on the field, the student's research topic, and the student's skills.
Do You Need a Master's Degree to Earn a Doctorate?
Doctoral programs in some disciplines accept only applicants with master's degrees. Other programs accept students right out of college, permitting them to earn a master's degree along the way.