There are different types of microscopes, but the most common for viewing small organisms are:

* Light microscope: This uses visible light to illuminate and magnify the specimen.

* Electron microscope: This uses a beam of electrons to illuminate and magnify the specimen. Electron microscopes offer much higher magnification than light microscopes and can reveal the fine details of cellular structures.

Both types of microscopes allow us to see organisms that are too small to be seen with the naked eye.