Reflecting on Why We Cite also includes examining How We Use Sources.
The BEAM model (Background, Exhibits, Argument, Method) is one illustration of the variety of ways we can use sources. We cite sources to achieve a variety of goals in our own work, and the same source could be used for different reasons in different contexts.
Bizup, Joseph. "BEAM: A Rhetorical Vocabulary for Teaching Research-Based Writing." Rhetoric Review vol. 27, no. 1, 2008, 72-86.