A pixel is a little square that makes up the image on your computer screen. For example, your computer's 17" monitor has a resolution of 1280 pixels wide by 1024 pixels tall. A digital camera's CCD can only capture so many of these pixels, which are then stored in memory, and later transferred to your computer.

If a camera can capture at a resolution of 1280 x 1024 (just like the above monitor), which is a little over 1,300,000 pixels (finding out the total pixels by multiply 1280 x 1024). The word "mega" is taken from the Greek word meaning "great", and usually means "one million". Hence, a camera with 1,000,000 pixels is a 1 Megapixel camera.