And the introduction of megapixel digital cameras and true photo-quality inkjet printers has made this capability much more attainable. But that means you'll need to add a few new terms to your technical vocabulary. At the heart of all digital cameras is a sensor, the electronic chip that takes incoming light and converts it to a digital file. The density of the sensor determines a camera's overall picture quality. More photosites on a sensor mean better image resolution and a larger final printed picture.
Resolution refers to the number of pixels in a picture.
VGA digital cameras are typically the least expensive cameras, because their small sensor captures just 300,000 pixels. These pixels are arranged in rows and columns, so a VGA image has 640 rows and 480 columns of pixels. The resulting 640 x 480 resolution image will look good on your computer or a web site, and it will print a very nice 4 x 6-inch print. But if you try to enlarge the print, you're going to see image degradation, because there just isn't enough information in a 300,000-pixel image to enlarge the photo beyond 4 x 6 inches. XGA and 1-megapixel cameras capture between 700,000 and 1.3 million pixels.