DPI [Dots Per Inch] != PPI [Pixels Per Inch] - this is a common misunderstanding when discussing screen resolution and they're not directly comparable. DPI has

DPI [Dots Per Inch] != PPI [Pixels Per Inch] - this is a common misunderstanding when discussing screen resolution and they're not directly comparable. DPI has to do with the printed image - how many of the smallest dots of ink can fit along an inch on paper. The resolvable image detail depends on this as well as other factors like the dithering algorithm. PPI defines how many groups of pixels (each normally made up of an R, G, and B sub-pixel) fit in a linear inch. Even this is complicated by things like some of the current OLED screens that have twice the number of green sub-pixels than red and blue. More: http://www.google.com/search?q=dpi+vs+ppi http://www.google.com/search?q=dpi+vs+ppi