how many pixels in an inch?

[benducket]

I attempt to learn how many pixels in an inch, since I often see different numbers, such as 72 PPI and 96 PPI, and I just do not understand. Is it influenced by the screen, or does it have a conventional value?

Can anybody explain it in a simple way?

 

[Luna]

It has no standard amount of pixels per inch, but rather a pixel density of the device (PPI: pixels per inch).

Examples:

Standard displays: 72–96 PPI

Many laptops/monitors: 100–150 PPI

Retina/hi-res phones: 300–500+ PPI

So 1 inch = device’s PPI pixels.