Compliance Accelerator 10 Application Searches / Roles vs Dept Searches / Roles

Hi,

What's the differrence between Compliance Accelerator 10 Application Searches vs Dept Searches?

You cannot delete or edit any searches in CA, is that normal? If yes why? In that case customer will have to make sure that they understand all aspects of the search and creates the search with correct settings that they need in first place?

Also what's the differrence between Department Roles / Role assignments and APP Roles / Role Assignments?

Basically what is the concept of Application Tab settings in CA Client?

Many Thanks