Arguably the most anticipated new feature in PlayStation 4 firmware update v2.50 is the ability to Suspend/Resume your game in Rest Mode, meaning that you can put your console in a low power state, without ever needing to close the application. There is some setup required before this will work, but follow the steps, and you'll be jumping in and out of your games in 15 seconds or less.
1. Go to Settings
From the PS4's home screen, push up on the DualShock 4 to reach the top layer of the system's menu, and scroll to the toolbox labelled 'Settings'. Select it with X on the controller.
2. Enter the Power Saving Settings submenu
When the long list of options appears, scroll down until you reach an option named 'Power Saving Settings', and select it.
3. Set Functions Available in Rest Mode
In this area, scroll down to the option named 'Set Functions Available in Rest Mode', and select it.
4. Turn on Suspend/Resume
You'll see a list of options available here. You want to scroll down to the one that reads 'Keep Applications Suspended' and ensure that the tick box to the right of it is filled.
5. Play a Game
With the setup complete, you can now play any game as you would normally. There are no limitations to Suspend/Resume, but, obviously, if you're playing online multiplayer, you will be disconnected when you enter the suspended state.
6. Suspend Your Game
When you're ready to suspend your game, hold down the PlayStation button on your DualShock 4 until the 'Quick Menu' appears. From here, you'll need to select 'Enter Rest Mode', and your console will start to power down. You'll be able to tell that you're in Rest Mode, as the light on the top of your device will turn orange.
7. Resume Your Game
When you're ready to play again, push the PlayStation button on your DualShock 4, and the system will start to wake up. Assuming that you've followed the steps above correctly, your game will appear in a suspended state, and you'll be able to start playing again straight away.