Q. What are the stacks?

Stacks: Shelves in the library where materials—typically books—are stored. Books in the stacks are normally arranged by call number. May be referred to as “book stacks” or "main stack".

This and other definitions of library terms come from the Association of College and Research Libraries' Multilingual Glossary for Today's Library Users

At the UW Library, the main stacks, or main collection, is located on the 5th floor of Centennial Hall (accessed by the main spiral staircase or elevator). It's also good to understand the difference the reference collection and the main stacks. For a complete list of location names, see here: libanswers.uwinnipeg.ca/faq/156297