What are the key differences between a PhD student and candidate?

The terms "PhD student" and "PhD candidate" are often used interchangeably, and there's no strict, universally defined difference. However, a subtle distinction exists based on progress in the program:

* PhD student: This is a broader term encompassing anyone enrolled in a PhD program, regardless of their stage of progress. It includes students in the early stages, still taking coursework and qualifying exams.

* PhD candidate: This term typically implies that the student has passed their qualifying examinations (or equivalent milestones) and is actively working on their dissertation research. They are *considered* a candidate for the PhD degree. They are closer to completion.

In short: all PhD candidates are PhD students, but not all PhD students are PhD candidates. The "candidate" status signals a significant advancement in the program.