The Ziff Davis Online Network defines dpi as an "Abbreviation of dots per inch, which indicates the resolution of images. The more dots per inch, the higher the resolution."

In other words, dpi indicates the quality of images and text that are going to be printed.

This can be confusing because dpi is used to refer to both the quality that a printer is capable of, as well as the quality of images that are going to be printed. And, to make things worse, it is used to describe screen resolutions for monitors, digital cameras and other digital graphics.

First, let's talk about traditional mediums like newspapers or magazines. Due to the quality of the paper they are printed on, newspaper equipment is only equipped to print images at about 150 dpi. Glossy, art magazine paper and equipment is of a much higher quality and can print very sharp images and graphics, up to 600 dpi.

Again, by having more dots in an inch, more information or image detail can be displayed in a given area, giving you higher quality, but, only as high as the medium can handle.

Similar to how the different quality of mediums can limit the maximum quality of what is printed on them, screen resolution is limited to 72 dpi. Of course, you can view images that are higher resolution than 72 dpi but the screen must enlarge the image in order to view it in its entirety.

For example, a 3x5" image at 72 dpi will display 3 inches across and 5 inches tall on your screen. However, a 3x5" at 144 dpi will display twice as large on your monitor because each inch has twice the number of dots and the screen can only display at 72 dots per inch. However, when you print them out, they both will be the same size, but the 144 dpi version will look better because there will be more image detail in the same area. Better image detail will result in brighter colors. bolder graphics and sharper images.

This information can be useful when buying a digital camera and printer. Often, cameras will list the maximum resolution at which that they can capture an image. It is common to see numbers like 640x480, 800x600, 1024x768, 1280x960 and so on. These refer to the size of the image in pixels at 72 dpi. You may also recognize these numbers as the screen resolution on your monitor because, as I mentioned before, your screen is based off of a 72 dpi resolution as well.

To explain this further, a pixel is the same as a dot in dpi. So if we take a picture that is 800 pixels wide and 600 pixels, or dots, tall it will translate into about 11.11 (800 pixels divided by 72 dpi resolution) inches wide by 8.3 inches tall, at 72 dpi, and will look that big on your screen.

Fortunately, we can increase the resolution, and the quality, by decreasing the size. By cutting the size in half, we can push all the pixels or dots closer together, creating a 144 dpi image resolution. Size the image down by half again and you could print a 288 dpi (decent quality) image, but it would only be about a 3"x2" image.

These days, 600 dpi color printers are becoming pretty common. And, as you might expect, an image printed at 72 dpi won't look very good on a printer capable of printing 600 dpi.

As I said before, this can get a little complicated, but it is important to at least recognize that, when using a digital camera, larger images can be taken, which will result in better quality images. And, with printers, unless you have an extremely high-end camera, it may not be necessary to spend the extra money on a printer that prints very high resolutions.