PlayStation Camera is the additional device and is sold separately from PS4. PS4 comes with PlayRoom which is a collection of games and demos to make use of playstation camera. There is a voice system allowed for PlayStation camera. You can say things aloud with this. If you would like to play a game, then go to games and just say the name of the game. The device displays you the game you want.
If you want to turn off the camera, you can turn off it by your voice commands. It has simple navigation and the camera uses its sensors to identify your face in a room. When it identifies you, it signs you into the Playstation. Without the need of pressing buttons on controller, the camera can read patterns on your. You can provide commentary with Twitch app. There are also many other voice commands.
Sure the camera is a great addition for players who want their gaming live stream. Voice and motion controls are the best things to show its best interface. Although it can be reached to its potential fully, yet it is a great product by sony.