As small hand-held devices displace the PC as our primary technology, the
subject of pixels becomes even more difficult to grasp.
The most striking issue of this evolution is that, often, the tiny individual points of color (pixel)
on a small hi-res screen often can not even be decerned by the human eye.
have evolved to the point that increased screen resolution may no longer offer a better
image or easier reading, but just manufacturer bragging rights. (Think Apple Retina) This is the same type of escalation that
happened in the digital camera industry. There comes a point where the increase in
resolution offers no attendent increase in the utility of a device.
"Pixel Density" has emerged as the metric by which most phones and tablets are compared.
Because of the wide range of physical dimensions, actual "screen resolution" is no longer an effective benchmark.
For example, a very small device might have a modest resolution (ex. 320 X 400) but, because of the tiny screen, appear
just as sharp as a larger device with more total resolution.
Here is a look at pixel density for popular tablets.
2560 X 1600
2048 X 1536
Kindle Fire HD9
1920 X 1200
Asus/Google Nexus 7
1280 X 800
Kindle Fire HD7
1024 X 600
1024 X 768
1024 X 768
As you might imagine, only those of us with superior vision can even see something as small
as 1/300th of an inch. Maybe you work in your yard and garden, that's about the same size as
the tiny stickers you may have struggled to remove.
*Wikipedia maintains a good list of screen data for various devices