Lightning App Builder allows administrators to drag and drop various standard and custom components to create a Lightning page.
The following screenshot shows the Lightning App Builder screen that administrators use to create a Lightning page:
Screenshot shows the Lightning App Builder Screen
Once a Lightning page is saved, the activation screen provides options to configure the profile for the page.
On the Record Page, the assignment configuration can be understood with the help of the following screenshot:
Clearly, one overrides the other. ORG DEFAULT is the top level, followed by APP DEFAULT, and then by APP, RECORD TYPE, AND PROFILE.