First of all, let me explain why you should know all this: Simply because understanding about DPI, PPI, resolution and image size is key to print something of quality or optimizing images for the web, saving you a lot of time and giving you the best results. So let’s see what is the meaning of each one.
Pixel is the unit of measurement for digital images. We can compare them to our body cells, which together build a kind of map to be interpreted by the computer or screen.
Pixels define the resolution
A high resolution image is an image with high density of pixels, that is, with several families of pixels in its composition. The greater the number of pixels, the higher the resolution, providing more details and better definition to the image. Logically, an image with low resolution will have less pixels, less details and definition.