• First things first: why do you want one?
• How digital cameras work
• Photo Terminology
• Camera features
• Storage
• Connectivity
• Power
• Image Compression
• Design
• Software
• Questions to ask the retailer

Dock

Some cameras don't connect directly to your PC, but instead sit in a dock, which in turn is connected to your machine, usually by a USB 2.0 connection. When docked, the camera will automatically connect to your computer, upload its images, and launch software for editing, e-mailing, and printing.

Cameras that use docks are generally aimed at novice users, and not many companies employ them any longer, with Kodak and Casio being the exceptions.

Video Out

High-end digital cameras usually come with the capability of recording video, and an audio visual (AV) output terminal. Using an AV cable, video can be transferred from your camera to your TV, VCR or PC. If transferring data to your TV, the AV cable will connect to its video in and audio in terminals.

Power

Most cameras include an AC adapter to charge batteries or run the camera from an outlet. Some cameras will charge batteries in-camera. However, there are still three types of batteries used in digital cameras, and each have their pros and cons.

Alkaline

These are your standard off-the-shelf AA-sized batteries. Their biggest selling point is their availability. Their weakness is that they don't last as long as other battery types. If you're going to use alkalines, be prepared to buy more batteries regularly.

Ni-MH

Ni-MH (Nickel Metal Hydride) are rechargeable, AA-sized batteries, and can be used in cameras that use AA-sized alkalines. While Ni-MH batteries last longer than alkalines, they don't last as long as lithiums. They're also environmentally friendly.

Li-ions

The longer lasting but most expensive types of batteries are Li-ion (lithium ion) batteries. Rechargeable Lithium ions have a predictable voltage curve which allows cameras to have a reliable "fuel gauge" indicating how much charge remains. The bad news about Li-ions is they are not available in standard sizes such as AA and are more difficult (expensive) to manufacture. Therefore, if your camera can use only Li-ions, you won't have much choice when it comes to buying extra batteries or faster battery chargers.

Lithium batteries come in standard sizes and voltages, deliver two to three times as many shots as alkaline batteries of the same size, and have a shelf life of up to 10 years. While they may be too expensive for everyday use, their shelf life and capacity make them the best choice.