A general biological microscope mainly consists of an objective lens, ocular lens, lens tube, stage, and reflector. An object placed on the stage is magnified through the objective lens. When the target is focused, a magnified image can be observed through the ocular lens.
Telescopes also have a similar structure; however, they are used for observing distant objects. A telescope receives light from a star or other distant object with the objective lens and adjusts the refracted light to the focal point through the ocular lens. On the other hand, a microscope is designed to emit light onto or through objects and magnify the transmitted or reflected light with the objective and ocular lenses.
Figure: Principle that enables magnified observation with a biological microscope