It may seem that there is only one telescope, but there are really lots of telescopes. There are about thirty different telescopes with a few different pieces that can be added onto them. However each of these thirty telescopes can be put into a certain category. Therefore, there are three different types of categories of telescopes.
These categories are refracting telescopes, reflecting telescopes and catadioptric telescopes. These telescopes work with optical spectrum. However, there are telescopes that work without optical spectrum.
They include the atmospheric telescope, infrared telescope, radio telescope, submillimeter telescope, ultraviolet telescope, and the X-ray telescope. The X-ray telescope has a type of telescope called the Wolter telescope. There are also different mounts that these telescopes can be mounted on.