When you have a book in hand and want to confirm that it's the book you were looking for, you can look at the book's identifiers, most of which are located on the title page. Examples of identifiers are the title, author, edition, year, ISBN (International Standard Book Number).
The process is similar if you want to identify a particular book in the catalogue, for example from a citation. You also want to look at the book's identifiers which are located in the description tab.
Once the tab is opened, you can see most of the book's bibliographic information. The publication information, edition and ISBN will help you identify the book. The OCLC number is the system's unique identifier, which can be useful to access a particular book quickly, however, the OCLC number is not part of the book's citation.
