Microscopes are tools that magnify objects too small to see with the naked eye. They have various parts including objectives, an eyepiece, stage, and light source. There are three main types - simple, compound, and electron microscopes. Compound microscopes use two sets of lenses to magnify objects up to 200 times, while electron microscopes can magnify objects up to 300,000 times using electrons rather than lenses. Microscopes are used by scientists to study living and non-living tiny specimens.