Cornell's library Catalog is where you can go to search for books. The main search box will allow to search by keyword, author, and a few other options selectable from the "All Fields" dropdown.

On the search results page, you'll see a full list of "limiters" (such as "Format", "Publication Year" and "Language") on the left hand side that will allow you to narrow down the number of results. The right hand side will have your list of results. Any results that have a library and a call number available will tell you where the book can be found. This option for example, can be found in Mann Library:

At Cornell, we use the Library of Congress Call number system to organize our book stacks.
Books that are listed as being in the "Annex" can be requested for Delivery. The books generally take less than 24 hours to be delivered to the library of your choice. You can also request books from other libraries across campus to be delivered to the library of your choice if that's your preference. To request a book for delivery, click on the book title to open up the item record, then in the item record select "Request Item", or "Request scan of article/chapter" if you'd prefer to just have a digital copy of a part of the book.

Finally, for any books that are marked as being "online", a "Connect to Full Text" link will be available in the "Availability" box in the item record.

Mann Library has quite a few technology options available for check-out. These include
Olin Library also has several technology borrowing options available.
Requesting Books via BorrowDirect or Interlibrary Loan:
Whenever you want access to a book that is not available at Cornell, you can request that book through BorrowDirect or Interlibrary Loan. The difference between the two is that BorrowDirect is a partnership with fewer libraries, but it's usually quicker (3-5 days). Interlibrary Loan is a partnership with most academic libraries across the country, but on average it takes a bit longer (3-14 days).
Alternatively, if you come across a book in our catalog that is checked out, you may use the "Request" button in the catalog record to find a different copy. If no copy is available at Cornell, this Request option will direct you to BorrowDirect or Interlibrary Loan.

To confirm, yes you can use BorrowDirect/ILL to request books that Cornell owns but that are not currently available. As a matter of fact, this is encouraged.
You can also ask the library to buy material you think we should have. Recommend a Purchase or learn more about our Library Collections.
