Libraries have their own "language". While you may be familiar with library terminology in your own language or in British English, terms used in American libraries may be new to you.
Here is a glossary of common library words. See also the Multilingual Glossary for Today's Library Users (includes Definitions (explanations of the terms) and Language table (translations of popular library terms into Arabic, Chinese, French, Korean, Spanish, and Vietnamese).
In the library catalog and on some Web pages library locations are abbreviated (CEAS, REF, etc.). Abbreviations for library locations can be found in Symbols & Locations (PDF file).