Share Play is a new feature introduced on the PlayStation 4 with the 2.00 system update. It allows a PlayStation Plus member to invite another user to watch or share a game through a 60 minutes (max) session.
A PlayStation Plus membership is required to host Share Play sessions.
A good internet connection as SharePlay sessions requires much bandwidth.
How to host a SharePlay Session
To start a SharePlay session, simply press on the Share button of your Dualshock 4 controller and then select Start a SharePlay > Ok . SharePlay is now available in the Party menu, simply select the user you want to invite. An invitation will be sent to the user and the SharePlay session will start once it has been accepted. The user (visitor) doesn't necessarily need to own or download the selected game to join the SharePlay session. At this point the user is already seeing what's happening on your screen.
Sharing your controller
Once the session has stated, the host can access the other sharing options through the SharePlay menu. Click on the Share button of your controller > Go to Party for Share Play > Give Controller to Visitor. Two options are available:
Allow the visitor to play as you - Allows the host to hand over his controller to the visitor even if the latter doesn't own a PlayStation Plus membership. You are stucked on a difficult section of a game or unable to get a particular achievement? Feel free to hand over your controller to any of your friends for him to try.
Play a Game Together - Virtually hand over the second controller of your console to the visitor and enjoy multiplayer game together (both users require a PlayStation Plus membership).
End a SharePlay session
The SharePlay session ends after 60 minutes, but you can also stop it manually. Tap on the Share button > Share Play > Stop Shareplay.