And regarding the systems themselves, these are the differences (again using Google Translate)
"Discover Media" navigation system.
The system with a 20.3 cm (8-inch) color touch display including proximity sensors, 4x 20 watts of power and six loudspeakers offers hybrid navigation, a selection of various map options, free map updates via the Internet, 32GB media memory, two external USB and a Bluetooth interface, hybrid voice control and Internet radio. The system supports wireless AppConnect, We Connect and We Connect Plus
"Discover Pro" navigation system
In addition to the functions of the "Discover Media" navigation system, the system offers a 23.4 cm (9.2 inch) color touch display including proximity sensors, a simultaneous display of the navigation map on the digital cockpit8) and the Screen of the navigation system, 64GB media memory and DAB +.
Multi-function display "Premium". Displays important driving and vehicle information in 3D and in color.
Voice control. Control numerous telephone, navigation and audio functions via voice.
Mobile phone interface "Comfort" including inductive charging function. Improves reception and wirelessly charges the battery of compatible smartphones