The magnification power of a light microscope is achieved by multiplying the power of the eyepieces by the power of the respective objective lens
There are two broad categories of light microscope: Stereo and Compound. Stereo are Low Power or Dissecting microscopes. Compound are High Power or Biological microscopes.
Stereo microscopes are used for macro specimens that are visible to the naked eye (insects, crysatsl, pcb etc). Compound are for viewing cells (on microscope slides) that are not visible to the naked eye.
A digital microscope can be achieved by simply adding a digital microscope camera to a standard microscope - while retaining maximum flexibility
The resolution of a digital microscope camera is limited by the resolution of your computer monitor. High resolution (typically, above 3MP) may be wasted.