Telescopes are instruments by which one can see sky in great details. There are different ground based and space based telescopes.
To observe light from different astronomical objects in different wavelengths, we need different kind of telescopes equipped with different technologies. For example, X-ray emission from different astronomical sources can not be observed by ground based telescopes as atmosphere will absorb most of the X-ray photons. It can be studied by various telescopes in space (like Chandra, XMM Newton, Integral etc).