The concepts of electricity and magnetism in physics are complex and demanding to learn because their meaning builds through several different phenomenological areas. Each of the phenomenological areas adds a certain facet of the meaning of the concept. All standard physics textbooks discuss at least 1) force, 2) energy and work, and 3) electric charge and current, which are different phenomenological facets of the field and which also are implicitly covered in instruction. It is of interest to ask, how these three facets are actually reflected in university students' declarative (expressed and communicated) knowledge of electric and magnetic field concepts. Here this problem is addressed using recently introduced concept networks as a research tool. Using these concept networks, pre-service physics teachers have represented their views how electric and magnetic field concepts are linked to other concepts and conceptual elements in electricity and magnetism. The results suggest that more extensive is the students' basis of content knowledge the more balanced are the facets, while students with less extensive basis of content knowledge tend to favour forcebased understanding of the electric and magnetic fields. The implications of the findings on teaching and instruction are discussed.