1. ISO indicates the light sensitivity of the camera's image sensor. Set higher ISOs (above 400) to brighten dark image.
2. Optical Zoom vs. Digital Zoom Optical zoom is good; it brings your subject closer without sacrificing quality. Digital zoom is mostly bad; it crops your image and enlarges the remaining pixels to fill the space, resulting in a loss of quality.
3. Image Stabilization: Optical vs. digital
Optical stabilization is good. It mechanically detects and corrects camera vibrations that could blur images. Digital stabilization is mostly bad; it attempts to reduce blur by increasing the shutter speed, which could also add more digital "noise" to the image.
4. Shutter Lag refers to the milliseconds that elapse between pressing the button and taking a photo–a critical delay that can cause you to miss the action.
5. HD Photos and Video Shooting high definition-quality photos and videos requires a widescreen aspect ratio (the numerical relationship between the width and the height of an image) of 16:9 (think movie theater), which is the same dimensions as a widescreen HDTV, instead of the standard definition aspect ratios of 3:2 or 4:3. Before you shoot HD-quality video, be sure your video playback and editing software can handle it–shooting in standard definition (640x480) is always a safe bet.
6. Megapixels This number, set by the chip-size of your camera, determines the maximum size of the photo you can print.
7. Memory Cards
Digital cameras store images on several types of removable flash memory cards. Choose cards with between 2 and 4GB of storage space.