BOM Usage and BOM Category -authorization controls

Hi Team ,

We are working some of BOM authorization controls. Wanted to get clarified on the difference and usage of BOM Category and BOM usage .

Efficient way to control user authorizations is at BOM category level/usage level ?

As we enter at BOM functions the usage only will the BOM category gets referenced from where ? We dont do any customization for BOM categories right ??

Request your inputs on this , please ..

Thanks ,

MK