Why is a section, application, or profile greyed out in profile builder?

In profile Builder and noticed a section, profile, or application is greyed out. What does that mean?

When you go into profile builder and a section is greyed out, that means it is not added in a profile or application. If it is not added, it is not being used. 

When you create a new section, it must be added to the application or profile for it to be used. 

If you have it in the application, you must also add it to the profile to see the section/response.

If you only want it in the profile, you don't need to add it to the application.