Sophos Central Mobile Management Modes

Hello Everybody

I used to install sophos MDM a couple of years ago but now things have changed; I just tried to see if there is a Sophos course for the new software but I found nothing.

I have a customer that configured sophos mobile by himself; and the configuration in my opinion is pretty wrong.

To start understanding the environment I downloaded the devices he installed and I found that there are two Management Modes:

Device Mode

Mobile Threat Defense Mode.

Can anyone please explain me the difference?

Can anyone address me to some decent documentation that explain the new environment?

In the past there were courses that explained the system; now I found the administrator manual that in its 350 pages does not expalin much to give an idea of the system.

Thank you and best regards