AllSync & AllDup

When you are running a copy operation, there are a few options to choose, i.e.:
Set application priority to 'low'
Reduce the number of hard disk accesses per second

And:
Upon completing the copy operation:

• Shut down computer
• Shut down Windows
• etc...

What is the difference between "Shut down computer" and "Shut down Windows"?

Shut down computer:
Shuts down the system and turns off the power. The system must support the power-off feature.

Shut down Windows:
Shuts down the system to a point at which it is safe to turn off the power.