Midi Learn On/Off
At the very bottom of the right column in The Script Editor is MIDI Learn section.
The names of all connected midi devices will be displayed along with the last received midi message (MIDI Type/Channel/Value/Velocity).
MIDI Monitoring is used to listen to MIDI messages transmitted by any MIDI devices which are connected to your computer.
If the MIDI Learn button is turned on, when you have controller input settings form open and move a physical input on your midi controller, its MIDI data will be automatically input into the MIDI data section in the form.