Display, Printing, DPI and PPI
Photo.net have published a basic and easily understandable guide to the often confusing subject of image size:
“The confusion seems to arise because people aren’t sure of how these are related. They wonder if ppi affects the size of the image you see on a monitor screen. We know that displays are measured in pixels (e.g. a 1024x1280 display), and that screens are a given with (e.g. 15”), it seems logical that the pixels/inch setting should affect the size of the displayed image. Logical maybe, but wrong. Although monitors do have a measurable figure for ppi (pixels per inch), the ppi information in an image is NOT used for monitor display in web browsers.”