These allow you to keep taking pictures without having to offload pictures to a computer. Universal Serial Bus connection. A USB cable is the fastest, simplest way to port pictures from camera to computer. Older, cheaper cameras use slower, clunkier serial ports. An optical zoom.
Optical zooms are more functional and take better images.
Most low-end cameras have fuzzier digital zooms. An AC adapter. Usually offered as accessory, AC adapters save money. With color liquid crystal display screens for reviewing images, digital cameras drain batteries like jets drain fuel. You'll want to be able to plug your camera into an outlet while reviewing photos on the LCD, transferring images to your computer, or shooting indoors, if possible.