Vishal,
Here are a few high level definitions:
Planning Area is the database where data is stored.
Planning book is a custom program that reads, displays, and allows changes to the content of the Planning Area database.
Data View is a subset of the Planning Book. There can be multiple Data Views for each Planning Book.
Macros are custom programs that are attached to either the Planning Books or the Data Views.
There can be multiple Planning Books for a single Planning Area.
When you execute an //MC8E-related job, you typically define the Planning area, the Planning Book, the Planning Version, the Data View, and the Selection ID.
Selection IDs are another set of custom programs that are integrated with the Planning books. These permit restricting the data that is loaded into the planning book for viewing/maintenance.
For more info, see
Planning Book Maintenance - Planning Area Administration - SAP Library
Best Regards,
DB49