As you open the Hack application you will access the Clubhouse. As you can see the Clubhouse has this big switch that can be turned on and off.
When the switch is turned on, the environment changes as you enter the Hack mode, you will notice that the desktop and cursor become different. This will also allow you to browse through the different pathways that hack features, such as:
Once you are finished playing Hack, you can turn the switch off and keep using your computer as a regular computer. Toggle between on and off as you wish.