Difference between Standby in OMV menu and suspend from autoshutdown?

Hi
When I reboot my NAS and let the autoshutdown suspends it (with command 'systemctl suspend' according to the log), I cannot wake it with WakeOnLan.
When I reboot my NAS and use OMV's
Standby menu (I couldn't find the used command), I can wake it with WakeOnLan; after that, if I let autoshutdown suspend it, I'll be able use WakeOnLan on it.

Can someone explain me the difference? Isn't standby and suspend the same in debian? Which command does OMV use for 'standby'?

Thanks for your help!