How else can spatial resolution be reported?

• A. Pixels per inch
• B. DPI or PPI
• C. Dots per inch
• D. Resolution units are megapixels

Answer: (B)

Spatial resolution is about how much detail fits into a given length, so it’s described as how many samples appear per inch. In practice, you’ll see it reported in two common ways: pixels per inch for digital images and displays, and dots per inch for printed output. Dots per inch is essentially the same idea as DPI, just oriented toward printers and ink droplets. Pixels per inch covers digital sampling density, while DPI covers output density. The phrase that covers both contexts—DPI or PPI—recognizes that resolution can be described for either the image itself or the printed result. Megapixels, by contrast, measure total pixel count, not density per inch, so it doesn’t express spatial resolution per inch. So, reporting as DPI or PPI is the most complete and flexible way to express spatial resolution across media.