A pixel is a colored dot that makes up a digital picture. Pixel resolution is measured per square inch of space; the more pixels there are per square inch, the higher the resolution and the better the picture.

• 256x256 - Found on very cheap cameras, this resolution is so low that the picture quality is almost always unacceptable. This is 65,000 total pixels.
• 640x480 - This is the low end on most "real" cameras. This resolution is ideal for e-mailing pictures or posting pictures on a Web site.
• 1216x912 - This is a "megapixel" image size -- 1,109,000 total pixels -- good for printing pictures.
• 1600x1200 - With almost 2 million total pixels, this is "high resolution." You can print a 4x5 inch print taken at this resolution with the same quality that you would get from a photo lab.
• 2240x1680 - Found on 4 megapixel cameras -- the current standard -- this allows even larger printed photos, with good quality for prints up to 16x20 inches.
• 4064x2704 - A top-of-the-line digital camera with 11.1 megapixels takes pictures at this resolution. At this setting, you can create 13.5x9 inch prints with no loss of picture quality.

With a 3 megapixel camera, the resolution is greater than most computer monitors can display. For print pictures, however, the higher resolution is necessary or the picture quality will be degraded. Hewlett-Packard estimates that 35mm film quality is approximately 20 million pixels.