Electron microscopes differ from light microscopes because they use a beam of:

1. A microscope resolves detail by the wavelength of whatever it sends through the sample. 2. Light microscopes send a beam of light. 3. Electron microscopes use a beam of electrons instead of a beam of light. 4. The far shorter wavelength of electrons is what lets them resolve organelles. _Source: OpenStax Biology for AP(R) Courses (CC BY 4.0), Ch 4 'Cell Structure', sections 4.1-4.6_