CompactFlash: The most widely used digital memory format, CompactFlash cards are used by most current Canon and Nikon cameras, as well as many other brands. CompactFlash cards are available in sizes up to 2 Gigabytes, larger than any other currently-available format.

Digital Zoom: Most digital cameras provide two methods for zooming: optical and digital. Unlike optical zoom, which uses the optics of the lens to magnify the size of an image, digital zoom discards pixels around the edge of an image, fitting the remaining pixels into the same space to give the appearance of zoom. Since digital zoom comes at the expense of resolution, you should always choose a camera based on its optical zoom, not the digital or combined figure.

Extended Zoom: Extended zoom digital cameras offer 8x optical zoom or greater, providing far more telephoto power than most other digital cameras (the average digital camera offers 3- or 4x optical zoom). On most digital cameras, a 10x optical zoom is approximately the equivalent of a 380mm lens.

Image Noise: Image noise creates specks of the wrong color in a digital image. Image noise usually occurs in low-light conditions when a camera's light sensor registers an incorrect value, for instance recording yellow when it should record black. This error causes small dots to appear in the image. Higher quality cameras should have very little noise, even at high ISO settings.

ISO: ISO is a measurement of a digital camera's imaging sensor's sensitivity. Digital cameras with high ISO capability are better able to take low-light images and pictures of fast moving objects.

JPEG: An acronym for Joint Photographic Experts Group, a JPEG is the most commonly used type of digital image format. By eliminating very subtle color distinctions that the human eye usually cannot detect, JPEG images are compressed so that they can save faster and use less space. Because JPEG format actually alters an image, it's compression is said to be "lossy," meaning that a certain amount of data is lost every time a JPEG is edited, saved, and compressed again.

Macro Mode: Macro mode allows a digital camera to take close-up pictures of small objects like flowers, insects, coins, etc. Macro capabilities vary by camera- check a camera's reviews to see how its macro mode performs.

Megabyte: A megabyte (MB) is a unit of data used to describe the size of digital images and the capacity of a digital memory card. Memory cards are available in sizes ranging from 8MB to 2 Gigabytes (a Gigabyte is the equivalent of 1,024MB).

Megapixel: A measure of resolution that reflects the ability of a digital camera to record detail. The more megapixels a camera has, the more detail its images can contain and the more they can be enlarged without losing clarity. More megapixels aren't always necessary, however.

Memory Stick: Memory Stick is a memory format used primarily by Sony digital cameras. Memory Sticks are available in sizes up to 1 Gigabyte.

Movie Mode: Movie mode lets digital cameras shoot video clips. Some cameras offer sound, while others can only take silent videos. The maximum length of a movie is determined by a camera's internal limits and/or the size of the memory card.

Optical Zoom: Optical zoom magnifies the size of an image by adjusting the lens. Unlike digital zoom, optical zoom enlarges the subject without sacrificing resolution.

Point and Shoot: A point and shoot camera offers few or no manual controls and very simple operation. Focus, exposure, and most other adjustments are completely automatic; all the owner needs to do is aim and push the shutter button. Most advanced cameras also have point and shoot modes.

RAW: One of the image formats available on some advanced digital cameras. RAW images are large, usually uncompressed files that, unlike JPEGs, are not processed by the camera and retain all their original data. RAW images are ideal for those who plan on editing their pictures with image-editing software. RAW images may require special software to turn them into a more common format like TIFF or JPEG.

Redeye: Redeye is the term used to describe the red color often visible people's eyes when a picture is taken with a flash. Redeye is caused by the reflection of the flash off the subjects' eyes -- a problem that is compounded when the flash is positioned close to the lens, as it is on many small cameras.

Redeye Reduction: By firing the flash several times just before exposing a photo, cameras with a redeye reduction feature cause a subject's pupils to contract, reducing the reflection that causes redeye.

SLR Camera: The most expensive of all digital cameras, digital SLRs offer complete manual control, higher resolution, advanced exposure control, and the benefits of detachable lenses. Due to the lens design, digital SLR's are not capable of shooting video.

SLR-Style Camera: With protruding lenses and large hand grips, SLR-styles cameras have bodies that are physically similar to actual SLR cameras. Unlike proper SLRs, however, these cameras do not have "through-the-lens" viewfinders and do not accept interchangeable lenses.

SmartMedia: A digital camera memory format currently used by some Olympus and Fuji cameras. These companies are using xD-Picture cards in their newer cameras, raising the possibility that the SmartMedia format is on the way out. SmartMedia cards are available in sizes up to 128MB.

TIFF: Short for Tagged Image File Format, TIFF is an image file format that does not lose any quality when it is saved and compressed. Many advanced cameras offer a TIFF format option.

Ultra Compact Camera: Ultra compact cameras are generally one inch or less thick, and small enough to be held in the palm of a hand. While these cameras do not offer all the manual controls of larger models, they still are capable of producing high quality images.

xD-Picture Card: Released in Early 2002 by Olympus and Fuji, xD-Picture Card is the newest digital camera memory format. Physically smaller than all other memory formats, and available (as of 5/03) in sizes up to 256MB, the xD-Picture Card appears poised to replace the older SmartMedia format.