We are all used to seeing the amazing pictures provided by optical telescopes, whether from Earth’s surface or in space (such as the Hubble Space Telescope). However visible light is not the only option for astronomy, there is useful information right across the full range of the EM spectrum that can be useful for astronomy. Most of this spectrum is blocked out by the atmosphere, with the exception of visible light and also radio waves. This allows us to do radio astronomy from the surface of the earth, and provide a completely different view on what is occurring in the universe. This talk will introduce the technology that allows us to perform radio astronomy observations by asking the question, what is a radio telescope?