You'd think you could enter any words that describe your topic as a Subject Search in the Online Catalog. However, the Subject Search uses special terms to organize books by subject. These are called Library of Congress Subject Headings (LCSH)

If you enter your keywords as a Subject search, you may not get much back. For example:

If you entered a Subject Heading search for: acquired immune deficiency you would get 3 books!

But if you searched using the LCSH term, AIDS (Disease) you'd see the library has many books.