Firstly, it’s worth pointing out that Photoshop uses the term "Resolution" to mean both PPI and DPI. PPI, or pixels per inch, is relevant only when viewing the image on a screen, while DPI is ...

DPI stands for dots per inch and refers to the number of physical dots per inch on a printed document. But when working on a computer - and using apps like Photoshop - we are measuring by PPI ...