Electron microscopes and compound microscopes are both used to view very small objects, but they do so in very different ways.
Compound microscopes use lenses to magnify an image up to 1,000x its original size. This type of microscope is limited in its ability to resolve objects and thus cannot be used to view objects smaller than 200 nanometers. Also, because compound microscopes rely on visible light, they cannot be used to view living cells.
Electron microscopes, on the other hand, use a beam of electrons to magnify an image up to one million times its original size, allowing users to see objects as small as 0.2 nanometers. In addition, electron microscopes can be used to view living cells because they do not rely on visible light. However, electron microscopes are much more expensive and require a vacuum environment to function, making them more difficult to use and maintain.