Landscape mode is a the orientation of the page that prints the image horizontally across the page instead of vertically. Landscape mode is commonly used to print charts or other images and text that may not fit properly vertically on the page. In the image to the right, is an example of the printer paper orientation setup through printer options. As can be seen in the picture, the top example is a paper orientation selected as portrait and the bottom is selected as Landscape.
Tip: When in portrait the page is taller than it is wider and when in landscape the paper would be wider than it is tall.