Basically both operate by bouncing tiny particles or waves off of objects in order to make them visible. Electrons are smaller than light photons so we can see smaller objects clearly with electron microscopes. There are disadvantages though. First, color is a function of light wave frequency so we can't see electron micrographs in color. Color can be added artificially though by computer to differentiate structures, (think photoshop). Also, we cannot see electrons so we make them visible by bouncing them off a cathode ray screen similar to a TV set or computer monitor