OneSearch has four options—each one searches different content and offers different filters.
When you start typing your search words, OneSearch autosuggests search options you can click.

Everything
Is the most comprehensive search. Searches all of the resources in the Library Catalog plus many of our digital subscriptions. It will show more items that you can access online immediately.
Library Catalog
Contains books (print and ebooks), journals, magazines, newspapers, DVDs, audiobooks, music scores, images, maps, TTU dissertations and theses, and archival collections. Use the right side drop-down menu to limit the search to only Architecture Collections, Southwest/Special Collections, Government Documents, and Digital Collections/ThinkTech.
Law Library
Books, journals, videos, and other items owned by the Law Library.
Course Reserves
Materials that instructors have selected to use in their classes—such as textbooks, supplemental readings (articles, book chapters), or films. They're either available online or kept "on reserve" at the Library with a shortened checkout time to give everyone in the class a chance to use them.