What’s a pixel, a megapixel, a DPI or a PPI? What does it mean when I see “1024 × 768 @ 72 PPI”? And why does it matter? These questions, and many more, are answered in this Live Training session. This is not a topic that’s Aperture specific—in fact, we only jump to Aperture once in this entire training. This is fundamental knowledge that’s critical to understand when exporting, posting, sharing, and printing your digital photography.