What is DisplayPort? DisplayPort is a digital display and data transfer interface developed by the Video Electronics Standards Association (VESA) in 2006. Like its contemporary competitors, HDMI and Thunderbolt, it is a composite format capable of carrying video, audio, and data simultaneously.
Locked Home Screen. One meaning of the term locked iPhone refers to an iPhone with a locked home screen. All iPhones have a lock feature that allows a user to lock his home screen when the phone is not in use to prevent him from accidentally activating the touch screen while the phone is in his pocket.
So, say, on your iPhone if you are playing a video with portrait lock enabled, the screen will not rotate. Or if you are swiping through pictures from your album, the screen will not rotate. iOS device in portrait mode (vertical). Bottom line: Activating Portrait orientation will lock the iOS screen in vertical mode.