how a display is positioned relative to the device showing it; most commonly refers to Portrait (tall and narrow) or Landscape (short and wide) but may also relate to upside down or laterally inverted displays

An image or display is shown on a device, such as a screen (or a piece of paper). The position of the display relative to the device showing it is often described as orientation, for example as portrait or landscape.

One context for this concept is in relation to screens that switch orientation. This is standard behaviour for phones and tablets, and some modern laptops and "hybrid" devices have the same feature. Displays may invert completely or switch between tall (portrait) and wide (landscape) style, requiring that the display be regenerated and at least some elements are resized

Portrait and Landscape orientations of a display:

Another possible context is in Libreoffice applications when setting print options: