Your instructor may require that you use scholarly articles in your research. These articles are also known as academic, or peer-reviewed articles. What she is asking you to use are journals that contain articles written by scholars in order to develop the body of knowledge in the subject areas in which they specialize.
This video clip from The Peabody Library will help you identify scholarly sources so that if your instructor requires you to use only scholarly sources, you'll know what she is talking about.