A pixel is the smallest unit of a digital image or graphic. Pixels are combined to form a complete image or video on the computer display.
When we zoom in on any image, we can see the image disappearing in a pool of small squares.
Those squares are the pixels. And the quality of the image is depended on those pixels or pixel density to be precise.
How is pixel density measured?
Pixel Density is usually measured in PPI (Pixels Per Inch), which refers to the number of pixels present per inch on the display.
A higher pixel density per inch ensures higher quality and vice versa.
FUN FACT: iPhone has a pixel density of 450 PPI.
What is MegaPixel?
Mega is Million. So Megapixel means a million pixels. Put it simply, a 9 MP digital camera can produce photos of 9 million pixels.