What is Public View Objects (PVO) and where can we use it?

Summary:

What is Public View Objects (PVO) and where can we use it? Can it be used in Data model for BI Publisher report?

Also, can we see the SQL or logic behind this PVO?

Example: There is PVO used as List of Values Source for Asset Book Parameter. And I want to see the logic or SQL written behind this PVO.

LOV attached to Asset book Parameter

Below is the List of Values Source definition.

Thanks,

Karun