System Metaphor
The system metaphor is a story that everyone - customers, programmers, and managers - can tell about how the system works. It's a naming concept for classes and methods that should make it easy for a team member to guess the functionality of a particular class/method, from its name only.

For example a library system may create loan_records(class) for borrowers(class), and if the item were to become overdue it may perform a make_overdue operation on a catalogue (class). For each class or operation the functionality is obvious to the entire team.


Resources
We would like to suggest you the following list of usefull resources on the topic: