In short the focus of PhD education is to prepare the RN to create original research. In contrast, DNP education is to prepare the RN to apply existing research to nursing practice.
Being a nurse practitioner (NP) is NOT the difference. Also while some PhDs become skilled in applying research to practice & some DNPs do research,…their doctoral course preparation & final projects are quite different!
For more information: Here’s a great comparison chart from one doctoral program: https://nursingandhealth.asu.edu/degree-programs/doctoral-vs-phd-degrees-at-asu