The word pixel was created from the two words “picture element”. From that they abbreviated taking the first few letters from “picture element” and it slowly became pixel. Now instead of anyone thinking of a pixel as an abbreviation they think of pixels as square dots. These pixels are what line up and create images on your computer screen, typically with 72 pixels per inch or PPI.When you print out a picture those pixels are translated onto paper at a rate of 100 to 300 dots per inch or DPI. There are millions of tiny little dots that have formed rows and columns so tightly knit so that you can’t see each individual pixel, instead you see a smooth ongoing picture full of different colors and ‘textures’.
Have you ever seen a pixelated image? A picture that looks like it’s made up of blurry “blocks”, instead of a smooth flowing picture of color? The pixelation effect is caused because the image was taken with less pixels than are trying to be shown and the computer is just putting in the required pixels and not taking into account how many pixels the “true” picture had. The computer only does what you tell it to, so when you get a pixelated picture it isn’t the computer or the picture’s fault, there just aren’t enough pixels recorded in that image data for that large of a picture. You can see to the left an example of a pixelated image or pixelation.
So from there you have megapixels. A megapixel is not a super awesome pixel, but rather a lot of pixels put together to form a picture or image.