In a nutshell, a digital camera uses a lens or series of lenses to focuses light onto a sensor. This sensor then records the image electronically and transfers it to the electronic workings of the camera where it is organized, converted into binary digital data, and then stored on fixed or removable memory to be later read by a computer. Of course this is a highly simplified explanation of how a digital camera works.

When it comes to the sensor, most digital cameras use a charge-coupled device (CCD), while other cameras use a complementary metal oxide semiconductor (CMOS) instead. Both sensors convert light into electrical charges, which are then read by the electronics in the camera and transferred to the relevant storage media.

As we all learned in grade school, there are three primary colors. Digital cameras use filters to divide the light into those three colors during the conversion process. Good quality cameras have three separate sensors for filtering, with each sensor matching one strand of light.

Aperture and shutter speed are the mechanisms used to control the amount of light that reaches the sensor. In most digital cameras the aperture setting is automatic, but some cameras also allow manual control. Professional photographers and enthusiasts prefer this option. The shutter, on the other hand, is set electronically.

There are four kinds of lenses used by digital cameras: optical-zoom lenses with automatic focus; fixed-focus, fixed-zoom lenses; digital-zoom lenses; and replaceable lens systems. Optical zoom lenses have both telephoto and wide options, while the fixed focus and fixed zoom lenses are used in the ordinary, inexpensive cameras that infrequent users own. The digital zoom lens creates the illusion of a zoom effect by culling pixels from the central part of the image and enlarging them to fill the frame. This, however, often results in a grainy or fuzzy image at the extreme limits of the camera's capabilities.

An LCD screen is standard on most digital cameras today, and they help in previewing images and also checking them out after taking a shot. Many screens are rather small, because there is only so much space on a camera for them. It is always best to transfer the images to a computer for viewing. In terms of image quality in general, the higher resolution the camera, the better the image quality.

For printing photos, resolution of the original image is also key. A low quality camera such as those found in many cell phones will create images that are really only useful for emailing or for web pages. A 2-megapixel camera produces images that can be blown up to about 4x6 inches. Four megapixels will create nice 16x20 inch images, but with falling prices on most digital cameras, if you enjoy photography and enlarging photos, don't settle for less than six megapixels.

Early digital cameras stored images on memory resources built into the camera. Images were then transferred to computers with the help of cables. Most modern digital camera makers utilize reusable and removable storage devices. These devices include SmartMedia cards, CompactFlash cards and other memory sticks. Other, less common removable storage devices include hard disks or microdrives, and writeable CDs or DVDs. These options have considerably enhanced the volume of visual data that can be stored as well as the overall flexibility of the modern digital camera.