Lenses are categorized as wide-angle, normal, telephoto, or zoom. A zoom lens enables the focal length to change within a specific range. Lens speed determines how much light is needed to take a picture. A fast lens enables you to take a better picture in a lower light environment than a slower lens. Digital zoom enables zooming through the use of software.
Optical zoom provides a far better image than digital zoom.
It does not, however, accurately represent the image that you're taking. In contrast, a LCD is a television-like screen that shows you what your picture will look like. Serial cables are the slowest by a relatively high factor. Different formats also have implications for quality and the capability of the file to be used and viewed by software applications. If you need more powerful flash capabilities, find out whether the camera can be used with an external flash.