In module 09, Central Electrics, what is Development Mode?

I was on my way to making a backup file of this module when I accidentally switched to Development Mode from the "Change Service" heading within module 09. There was no checkmark to confirm the change. I had no idea which mode was the default mode.

Here's the history:

---------------------------------------------------------------
Diagnostic session
Control unit: 09 Central Electrics
Value: Development mode
Mileage: 2340 km
Date: 2018-03-26 18:31


Can someone tell me what Development Mode enables/does in this module, and what the default should be so I can switch it back?

Thanks in advance.