It will open in a new window, just like your browser or any other application. For example, here I have Z17 and Z18 running side by side in a single monitor:
Notice the scrollbars at the bottom. Since the windows are smaller than the resolution of each of the guest operating systems, I can't see the full view. You can maximize them, of course, just like any other window. And if you do have another monitor, you can have it running at that same resolution in there.
Best way to learn is to just play around with that for a while, you'll get the hang of it soon enough.
Another option is to run something like Winboat. It's also virtualization, but specific for running Windows.