What are the differences between HTML5 and (pre-5) HTML? How can I make HTML-like forms in Markdown? What is difference between Hypertext and Markup in HTML?
You set the inches and the number of pixels in each of those inches. Photoshop removes or adds data to fit the number of pixels in each of the inches you specified. Note: The original image used in the examples below is 4x4 inches, 100 ppi, 400x400 pixels at 468.8 KB.
The dimensions and file size shown here are of the full size version of the photo above (the insect on the flower) before I resized it to something more suitable for a web page. So here, Photoshop is telling me that my photo has a width of 3456 pixels and a height of 2304 pixels.