The Functions page lists the functions of the system to a very granular level and provides an ability to enable or disable functions across roles.
Clicking on any specific function will display what groups have access to the function.
By using the Add and Remove controls, these functions can be customised to provide the correct level of access required.
The Export function will dump all of these settings into Excel so they can be seen on a single screen.
While those cannot be edited and re-imported, the primary purpose is to be able to compare the function security settings between different systems, i.e. between a dev site and a production site.
This is the basic layout of the exported file: