Rest Mode is one of the handiest features of the PlayStation 4. Instead of powering down completely, your console just goes into a low-power sleep mode (like your laptop does when it hibernates). This means that it’s quicker to start up, can charge the controller, and best of all, can download updates and games from the PlayStation 4.
By default, though, my console wouldn’t download games or updates when it was in rest mode. I discovered this when I left Dishonored 2 downloading overnight—or rather, thought I left Dishonored 2 downloading overnight. When I got up the next morning, it was still at 15%. Thankfully, the fix is simple.
Go to Settings > Power Saving Settings > Set Features Available in Rest Mode, and then check the Stay Connected to the Internet option.
Now, when you leave a game downloading overnight with your PlayStation 4 in Rest Mode, it will actually continue downloading.