Is there any way to understand pixel measurement unit??

Answer 1

To understand it you have to know your screen resolution, let's say that u have a screen with the resolution 1280 *720 this means that you have 921,600 pixels in the whole screen then divide it by square inches of that screen it will result the Pixels Per Inch (PPI).
This is how the distribution of the Pixels happens.
Then if the PPI was too much the - lets suppose-
a text will be smaller and vise versa.
As long as you practice you will truly understand.🤗

Answer 2

The best way to understand is to use them .