Q. What does "cited reference searching" mean?

A. To identify all the articles (and other documents, if possible) that reference a previously published article or book.

Q. Why is cited reference searching valuable to research? 

A. We can trace the scholarly conversation.  We can begin to learn which debates drive the conversation and which ideas concern the discipline.  We can identify influential articles and scholars.  We can discern how fields of scholarship developed, cohered, divided, and evolved over time.