Maybe I should have called it pixel resolution or display resolution to make it a little more clear, but given the context of the post I would have thought it made sense.

Resolution can have many and varied definitions, depending on the device being disucssed (ie. printer, display, graphic file). For a bitmap file being used on a touch screen with a defined size, I would think Pixels Per Inch would have less relevance as it has a fixed number of pixels. For raster graphics, images can be printed or displayed at variable resolutions depending on the capabilities of the output device so PPI would be more relevant.

So if a 42" Plasma Monitor has 1280x720 pixels, would you say that it has a resolution of 1280x720 or a resolution of ~35.5 Pixels Per Inch (horizontally)?

Or if a laser printer is capable of printing at 1200 DPI, would it have a resolution of 10200 x 13200 dots (on 8 1/2" x 11" paper) or 1200 DPI?

Thanks for pointing it out Ernie. Your attention to detail is impressive!