Both light microscopes and electron microscopes use radiation (light or electron beams) to form larger and more detailed images of objects (e.g. biological specimens, materials, crystal structures, etc.) than the human eye can produce unaided. (See also: What is eyesight ?)
An electron microscope is a microscope that uses beams of electrons instead of rays of visible light to form highly magnified images of tiny areas materials or biological specimens. Comparing light vs electron microscopes is made more complicated by the fact that there are different types of electron microscopes. The two main types of electron microscope are the Transmission Electron Microscope (TEM) and Scanning Electron Microscope (SEM). Other types of electron microscope include the Scanning Tunneling Microscope (STM) and Field Emission Transmission Microscope (FE-TEM).