What Does 'PhD' Stand For?

A PhD is the highest possible academic degree a student can obtain. PhD stands for “Doctor of Philosophy,” which refers to the immense knowledge a student gains when earning the degree. While you can actually get a PhD in philosophy, "Doctor of Philosophy" doesn't always refer to someone who has a terminal degree in that discipline. You can get a PhD in a number of fields, such as science or economics, and the word "Philosophy," translated from original Greek to mean "lover of wisdom," can refer to the degree holder's dedication to understanding a subject.

Students typically pursue a PhD when they're interested in an academic or research career—or if they want to take their education as far as it can go.

This article goes beyond the definition of a PhD, and touches on important information you’ll need to know about the degree, so you can decide whether pursuing one is the best choice for you. 

What is a PhD? 

A PhD is an academic degree that combines general knowledge of a field with specific mastery of an area of subtopic within that field. For example, earning your PhD in political science means you have a general foundation of the field, but likely also specialize in a more focused area, such as American or comparative politics, or political economy. 

PhDs—also known as doctorates—are terminal degrees, meaning they are the highest level of degree that you can achieve in certain fields, such as cognitive psychology, mathematics, English, economics, evolutionary biology, and public health. 

Read more: What Is a PhD?

What does it take to earn a PHD? 

PhD programs typically require you to complete advanced coursework, comprehensive exams that test your knowledge of your particular field of study, and a dissertation (or original body of research). The specific requirements will differ by program or university.  

How long does a PhD take?

Your PhD studies can take between four and seven years to complete, though it often depends on your field and other commitments. For example, it typically takes less than seven years to earn an engineering PhD, while it can take up to 12 years to earn an education PhD. Writing a dissertation is often credited with adding to the length of time it takes to complete a PhD program. In addition, some doctoral students may be working full-time or raising families while completing degree requirements, and thus may need additional time in their programs.

Learn more: How Long Does It Take to Get a PhD?

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Getting a PhD: what to know

If you're considering getting a PhD, there are some important aspects of doctoral degrees you'll need to know. 

To apply for PhD programs, you'll need to provide academic transcripts from your prior education, samples of your academic writing and research, and letters of recommendation from former professors. You will likely also need to write a personal statement that details your academic and professional goals, research interests, why you are applying to a particular program, relevant skills and experience, and strengths.  

Before applying, it's a good idea to research different education institutions to get an idea of their reputation, faculty achievements, mission statements, and the kinds of jobs former graduate students have gotten upon completing. 

Once enrolled in a doctoral program, expect to complete advanced study in your field. This will likely entail two years of coursework, conducting original research into a specific topic, navigating the world of academic publishing, and working closely with faculty to prepare for an academic or research-based career. 

Successful completion of a PhD program typically requires that you write a dissertation or conduct a significant research project on a specific topic related to your field. Most programs have students go through an oral defense to demonstrate mastery of the dissertation topic and describe its contribution to the field. 

PhDs vs. other terminal degrees

A PhD is not the only kind of terminal degree you can earn. In fact, there are two other types of terminal degrees that tend to be more career focused.

Professional doctorates

PhDs and professional doctorates are similar in that they are both the most advanced academic degrees you can earn, but a PhD requires a dissertation and a professional doctorate requires a doctoral study. 

PhDs are focused on producing original research, whereas professional doctorates typically have some professional experience they apply toward researching a solution to a practical problem. If you have significant experience in a professional field, such as business administration or public health, you might choose to pursue a professional doctorate because you can use your knowledge and expertise in more concrete ways. 

Professional degrees

A professional degree is the PhD equivalent for certain professions, like for a medical doctor, dentist, or lawyer. Whereas a PhD tends to promote a historical and theoretical education, a professional degree emphasizes a practical education because it’s designed for you to begin working in medicine or law after you graduate and pass additional licensing requirements. 

Did you know?

Honorary degrees at the PhD level are conferred upon people who've made significant contributions to a field or society at large. An "honorary" degree refers to an academic award that distinguished individuals can receive from an academic institution without having to complete the usual requirements of the degree. Here are some celebrity examples:

Meryl Streep has received honorary PhDs from Harvard, Yale, Princeton, and the University of Indiana at Bloomington for her cinematic achievements.

Oprah Winfrey has received honorary PhDs from Princeton, Howard University, Duke University, and Harvard for her philanthropic and business achievements.

John Legend has received honorary Doctorate of Music from the University of Pennsylvania and an honorary doctorate from Howard University.

Education requirements for a PhD 

Obtaining your PhD requires earning your bachelor’s degree and likely your master’s degree before you can begin applying to doctorate programs. However, there are some programs that combine the master’s degree with the PhD so that you spend less time earning both and can begin once you finish your bachelor’s degree. 

Let's look at the two most important degrees you’ll need to complete before you can begin pursuing your PhD.

Bachelor’s degree

You will need to earn a bachelor’s degree before pursuing more advanced degrees, like a master’s or PhD. You don’t have to choose a major related to your eventual doctorate, though it can help to pick a complementary subject so you have a strong foundation before taking higher-level coursework. For example, if you want to obtain a PhD in economics, then it might help to major in economics, finance, business, or even political science as an undergraduate. 

While graduate programs don’t always expect applicants to have studied the same field as the one they’re applying to, you will need to explain your interest in the field of your potential graduate work and have some knowledge about what you want to study within it. Aligning your undergraduate and graduate focuses may also help you move through your graduate coursework faster.  

Learn more: How to Get a Bachelor’s Degree

Master’s degree

A master’s degree is an advanced degree you can pursue after earning your undergraduate degree. PhD programs typically require a master’s before admitting you, though as we noted above, some programs may combine degree tracks to decrease the amount of time to completion.

Master’s degrees take between one and three years to finish, depending on whether you’re able to attend part-time or full-time. Master’s degrees enhance your level of expertise in your field, and you can pursue many higher-level careers with the credential—or continue with your education and apply to PhD programs. 

Learn more: Is a Master’s Degree Worth It?

4 benefits of a PhD 

There are a number of reasons why you might want to pursue your PhD. Let’s hone in on four of them: 

1. Become an expert.

People who obtain PhDs have the highest possible education in their field. As such, they're often considered to be genuine experts in that subject matter. You may feel a tremendous amount of personal satisfaction from having achieved this level of mastery.

2. Contribute original research. 

Adding to the knowledge of a particular field is no small feat. When you write your dissertation, you will have the opportunity to make a valuable original contribution that either expands people’s understanding of a subject or brings an entirely new perspective to it.

3. Broaden your job opportunities.

Earning a PhD could qualify you to work in academia or research, but it may also increase your qualifications—or help you stand out—for jobs that do not necessarily require a PhD. Holding a PhD may convey to employers that you’re knowledgeable, hardworking, and disciplined because of what it takes to earn the degree. 

4. Increase your salary potential.

On average, people with PhDs can potentially make more than those with undergraduate degrees, depending on your profession. The median weekly earnings of a person with a PhD in the United States is $1,885 compared to $1,305 for bachelor's degree holders [1]. A doctorate can also lead to higher lifetime earnings. A bachelor’s degree graduate will earn an average of $2.2 million over their lifetime, but PhD graduates earn an average of $4 million over their lifetimes [2].

Careers that typically require a PhD

A PhD is an academic credential necessary to teach at the university level or conduct high-level research in a number of fields, such as the life and social sciences. The following careers typically require a doctorate:

• Research associate

• Research scientist 

• Assistant professor 

• Dean of students

Careers where a PhD may help you advance 

While the careers listed below generally require a master’s degree, earning your PhD may help you qualify for more advanced roles within the profession—or help you develop more specialized knowledge to succeed in your career.  

• Historian

• Anthropologist 

• Statistician 

• Economist 

• Linguist 

• Political scientist 

• Psychologist 

Explore further

If you're contemplating getting your PhD and have not yet earned your master’s, explore a number of master’s degree options from prestigious universities in high-growth fields, such as computer science, business, management, or public health. Work toward your degree at your own pace from anywhere with an internet connection.