What is the difference between modern telescopes and and Isaac Newton's reflecting telescope?

The first microscopes were called Light Microscopes, and they work by passing visible light through whatever specimen is being observed and then through the glass lenses of the microscope. The lenses refract the light and magnify the image of the specimen as it is projected into the eye. Modern microscopes use beams of electrons instead of light. There are two main type of Electron Microscopes: Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM). SEMs are used to observe the surface of a specimen, and TEMs are used to observe the internal structure of specimens.