Since the Admin Interface would be not of much use if you could only use the Templates that the Admin Package ships with by default there is a Fallback System in place to automatically choose the most specific Template possible to Render the Admin Interface. The Fallbacks are Configured in the Settings.yaml and can be customized if needed.
The Admin Interface will check for the existence of each of this Fallbacks until a Template is found and then Render accordingly:
resource://@package/Private/Templates/@being/@action/@variant.html
resource://@package/Private/Templates/Admin/@action/@variant.html
resource://@package/Private/Templates/@being/@action.html
resource://@package/Private/Templates/Admin/@action.html
resource://Admin/Private/Templates/Standard/@action/@variant.html
resource://Admin/Private/Templates/Standard/@action.html
Partials are Subparts which can be Reused in more than one View (Form, Table, Toolbar,...):
resource://@package/Private/Partials/@being/@action/@partial/@variant.html
resource://@package/Private/Partials/@being/@action/@partial.html
resource://@package/Private/Partials/@being/@partial/@variant.html
resource://@package/Private/Partials/@being/@partial.html
resource://@package/Private/Partials/@action/@partial/@variant.html
resource://@package/Private/Partials/@action/@partial.html
resource://@package/Private/Partials/@partial/@variant.html
resource://@package/Private/Partials/@partial.html
resource://Admin/Private/Partials/@action/@partial.html
resource://Admin/Private/Partials/@action/@partial/@variant.html
resource://Admin/Private/Partials/@partial/@variant.html
resource://Admin/Private/Partials/@partial.html
resource://Admin/Private/Partials/@partial/Default.html
resource://@package/Private/Partials/@being/Widgets/@partial.html
resource://@package/Private/Partials/Widgets/@partial.html
resource://Admin/Private/Partials/Widgets/@partial.html
resource://@package/Private/Partials/@being/DashboardWidgets/@partial.html
resource://@package/Private/Partials/DashboardWidgets/@partial.html
resource://Admin/Private/Partials/DashboardWidgets/@partial.html