What is an Alternate Term?
Library catalogs and specialized article databases often define what they mean with the words and phrases they use. Our catalog uses "Library of Congress Subject Headings" as a way of making sure materials on the same subject come up, even if the author uses different words in the title.
For example, you can use the term "forest" or "timber." They both involve trees and forest, but the former has more biological connotations and the latter has more industrial connotations for what you would expect to find.