Putting screen densities into the correct bucket

Question

A set of six generalized densities:

ldpi (low) ~120dpi
mdpi (medium) ~160dpi
hdpi (high) ~240dpi
xhdpi (extra-high) ~320dpi
xxhdpi (extra-extra-high) ~480dpi         


        

Answer 1

When speaking about Android devices, PPI == DPI

PPI (Pixels Per Inch) and DPI (Dots Per Inch) mean the same thing since they are a measure of the density of the screen; thus, your approach about PPI vs DPI is correct.

A detailed explanation can be found here. The key part of the article is the following:

The screen density is quoted as Pixels Per Inch, PPI, and is the number of pixels that fit into an inch. The higher the number then the sharper images look on the display, therefore consumers consider a high PPI figure an advantage when buying a device. Sometimes the figure is quoted as Dots Per Inch, DPI ...