Many apps give you a different view when you rotate iPhone.

iPhone in vertical (portrait) orientation showing Calendar in day view. To the right iPhone is turned lengthwise, showing Calendar in week view

To lock the screen in portrait orientation, swipe up from the bottom edge of the screen to open Control Center, then tap the Portrait orientation lock button.

The Portrait orientation lock icon  appears in the status bar when the screen orientation is locked.

When you use iPhone 6 Plus or iPhone 6s Plus in landscape orientation, some apps have special layouts. These apps include:

  • Mail

  • Calendar

  • Settings

Note: These special layouts are not available when Display Zoom is enabled.