What is the difference (in simple terms) between height and width and device-width and device-height?
device-width is the...
width of the output device (meaning the entire screen or page, rather than just the rendering area, such as the document window).
Source.
The width...
describes the width of the rendering surface of the output device (such as the width of the document window, or the width of the page box on a printer)
Source.