Learn the lingo
The chosen notation for measuring image resolution. Mega is one million, so it simply means a million pixels. One megapixel (1MP) has an image resolution of about 1280 x 960 pixels, which should produce a reasonable 4 x 6-inch photo on an average inkjet printer.
Charge Coupled Device. A CCD is a light-capturing sensor that is the "film" of digital cameras. After an exposure, CCDs pass on the image information to the memory card (after some processing from the camera's electronics) in much the same way as film is altered by its exposure to light.
A shutter electronically regulates the amount of time that light can pass through the lens onto the CCD to create an image.
Most digital still cameras operate within the area of 1/60 of a second to about 1/1000, depending on the quality of the light and the effect you want to create. Shutter speed and the aperture work together to create the correct exposure.
Depth of field
The area in front of and behind the subject that is in focus. Smaller aperture settings put more of the foreground and background in focus while larger apertures do the opposite.
A fixed lens camera (no zoom) has a single focal length. The most popular lens on traditional 35mm film-based cameras was the 50mm lens due to its ability to most closely reproduce the viewing angle of the human eye. As the surface area of a CCD in most digital still cameras is smaller than 35mm film, the same viewing angle is achieved with a smaller lens, hence this is why the equivalent focal length is specified on digital cameras.
Flash memory cards
The solid-state media where digital images are stored. Several flash memory formats are used at the moment, so the camera you choose will generally determine what storage cards you need. The most popular formats include CompactFlash and Secure Digital, while all Sony cameras support Memory Stick. The xD-Picture Card format is a more recent arrival and is used in the latest Olympus and Fujifilm cameras.
The liquid crystal display (LCD) monitor is used to review, preview or act as a viewfinder. Most digital cameras have both an optical viewfinder and LCD monitor allowing you to switch between them. LCD monitors are normally between 1.5 and two inches measured diagonally. Some viewfinders can be flipped out of the body or angled up or down to make it easier to take low angle or high angle shots such as the Canon PowerShot G5 or Olympus Camedia C-8080.
The optical zoom lens in a camera allows you to get closer to the action by manipulating the elements of the lens. This means that if you have a 4MP camera and use the optical zoom to compose your shot, a 4MP image is the result. A digital zoom on the other hand interpolates the available pixels to enlarge an image.
Most digital still cameras provide presets to help you get the best shot under more challenging lighting situations such as snow, beach or night portraits. By providing the best shutter, aperture and white balance settings, all you need to do is select the appropriate "scene mode" and the camera takes care of the rest.
The time between you pressing the button and the camera actually responding to take the shot. The shorter the lag, the less annoying the camera is to use. Shutter lag is inherent in digital camera technology, but the degree of it varies greatly between models, which is why it pays to snap a few frames in the store to assess it.