Good researchers typically want to review a broad range of the existing scholarship on their topics. The process of examining relevant, previously-published materials is often referred to as conducting a "Review of the Literature" and many scholarly articles even feature a section called "Literature Review."
When you've found one article directly relevant to your research, the library's search engine makes it easier to find more like it. When you click on the title of an article that appears in your search results, you'll typically see a list of data about that article including publication information, an abstract, and often, a list of keywords, subjects, subject terms, or "descriptors" that can be used to begin a new, more focused search.
The terms used may vary, but most scholarly journal articles you find through the library's search engine will include a list of terms like those depicted above.
In addition, you'll also find a link on the left side of the page that says "Find Similar Results." Clicking this link will conduct a new search for articles that have the same or similar keywords, subject terms, or descriptors.
Finally, you can typically find a list of sources on related topics by carefully reviewing the References, Works Cited, or Bibliography at the end of any scholarly journal article.