What exactly is a mega pixel ?

Answer 1

In simplest terms possible, a "pixel" is a colored spot. Have you ever used a magnifying glass or microscope to look REALLY closely at newspaper print? Try it, and you will see the hundreds of tiny colored dots that make up each of the individual letters on the page. Digital images do the same thing, but with tiny colored squares known as pixels. In general, the more pixels there are to make up a single image, the greater definition that image will yield.

The word "mega", as you probably know, means million. Therefore one megapixel means that there are approximately one million tiny colored pixels which make up the image, while three megapixels means there are approximately three million of them.

That said, if you are asking about megapixels because you are interested in buying a camera (as is often the case), do yourself a favor and do not get sucked into the "more megapixels means better pictures" mindset. There is such a thing as too much of a good thing, you know. Decide how you will likely use your camera, and for what, and then ask an expert (who is not the one trying to sell you a camera) what features they recommend for your needs.

Answer 2

a megapixl is how meny millen dots

Answer 3

http://www.wisegeek.com/what-is-a-megapixel.htm