DPI isn’t the same as PPI. DPI, or dots per inch, is the amount of printed dots per inch when printed by a printer. It’s used to describe how many ink dots are placed on paper by a printer to create an image. PPI, or pixels per inch, is the number of pixels in one inch of an image displayed on a monitor. PPI is used to prepare images for printing. These two terms are often used interchangeably for various reasons. Firstly, even though the PPI refers to an on-screen image, it can affect the quality of the printed image. If an image contains fewer pixels, it won’t have much detail, and the quality will be reduced. The more pixels, the better. Secondly, both DPI and PPI are related to the clarity of the image. DPI is how the image looks when printed, and PPI is how the image looks on-screen. While PPI affects the quality of the printed image, DPI doesn’t affect the quality of the on-screen image in any way. It only refers to image quality when printed. Therefore, when we say we’re changing the DPI in Photoshop, we’re actually changing the PPI that affects the printed image and is transformed to DPI after printing.