Telescope is an optical instrument which is used for viewing heavenly bodies and distant objects. There are basically two types of telescopes:
Refraction Telescope Reflection Telescope
Refracting telescope uses a combination of lenses to form the images of distant objects. Astronomical telescope devised by Kepler and terrestrial telescope devised by Galileo are examples for refracting telescopes.
Reflecting telescope uses a combination of a lens and a concave mirror to obtain the images of distant objects.
