The document discusses telescopes and microscopes. It describes that telescopes use lenses or mirrors to magnify distant objects and make them appear closer. The two main types of telescopes are refracting and reflecting. Microscopes are used to view objects too small to be seen by the naked eye and the two primary types are optical and electron microscopes. Optical microscopes use lenses and light to magnify, while electron microscopes like transmission and scanning electron microscopes use focused electron beams instead of light.