In databases, the information (e.g., the title, the author's name, the publication date, the subject headings) are put into fields. When searching, you can limit your search to specific fields.
In this MLA International Bibliography example pictured below, the search is for an article on Huckleberry Finn written by the literary critic and novelist Toni Morrison. In the drop-down next to the search field with her name, the author field has been selected. Had this field not been selected, the results would have included articles and other sources that address Morrison's fictional works and those sources would have been written by a variety of critics.
In this ERIC example pictured below, Vietnam War is being searched as a subject. The researcher is focusing on the experience of Vietnamese refugee children attending elementary school in the United States. By making Vietnam War a subject field, all of the results will have Vietnam War as a subject.
