Librarians use the Library Catalog to organize the material intellectually. Various information (meta-data) is standard in Library catalogs all over the world. Generally the most important information to help you use it is:
Author = who wrote it.
- Helps to find other things written by this person.
Title = what it is called.
So I know if I've read it before, or heard of it, and will know how to quote it.
Call number & location = Where it is.
Tells you where in the Library to get it which section, which shelf?