The classification of the camera. Digital SLR is the most advanced camera type.
The amount of detail that the camera can capture is called the resolution, and is measured in mega pixels (MP). The more mega pixels a camera has, the more details it can capture and the larger pictures can be without becoming blurry.
The number of times the image can be enlarged with digital technology. Unlike the optical zoom, the digital zoom has no moving parts. Instead, it uses its digital brain to understand what it's "looking at", and digitally zooms in for a closer look.