Final answer:
Non-fiction books in the library are organized using either the Dewey Decimal system or the Library of Congress classification system to make it easier for users to locate specific materials.
Step-by-step explanation:
When searching for non-fiction books in the library, a catalog is typically used. The catalog may be in the form of a computer system. Non-fiction books are organized using either the Dewey Decimal system or the Library of Congress classification system. These systems assign a unique number to each book based on its subject matter, making it easier for users to locate specific non-fiction materials.