Telescopes are designed to work like the human eye, but with the capacity to collect much more light than a human eye can collect. This is why the “size” of a telescope is so important. The size refers to the telescope’s aperture, or diameter. Think of a telescope as a light collecting bucket. The diameter determines how much light can enter. The more light that can enter, the brighter the image. I am fond of referring to my telescope as my light bucket!
The 2 basic types of optical telescopes are REFRACTING TELESCOPES and REFLECTING TELESCOPES: