You can decide for each app whether to populate “global” content from the Master Site to all sites, or allow site admins to edit their own content for certain apps.
Change your mind whenever you feel comfortable in providing more control, or take control away as needed. With a click you can make any app “Global”, which will disable content editing on the app by site admins. Global apps display the content that you’ve saved in the Master Site on all of the websites that have the app installed.
In addition, you can control app placement, movement, and removal on the fly, determining what your site admins will have access to when managing their websites.