telescopes
There are two types of telescopes, refracting and reflecting.
Refracting
The refractor telescope is one of the earliest telescopes invented. The way that it works depends mainly on the glass lens at the front of the telescope. When light passes through the glass, it bends. This kind of telescope if expensive but it perfect for the beginners. They also have good quality and sharp images. The air current doesn't effect the image you see due to the tight air seal.
Reflecting Telescope
The way that the reflective telescope works depends on the mirror at the end of the telescope. The way that the mirror reflects the light results in the production of an image. This telescope is great if you want to look at something from a car distance or the has little light. The image you also see through this telescope is better quality than the refracting. The bad things about this things is that they are very fragile and have inaccurate images.