Radio technology enables the extension of astronomical observations beyond light to other frequency ranges. This has led to the discovery of numerous cosmic radio sources, the physical causes of which are explained as well as how a radio telescope works. Even small radio telescopes can observe radiation from the Sun and other radio sources, as well as the 21-cm radiation from the Milky Way. Through interferometry, much higher resolution can be achieved than with individual radio telescopes. As a result, radio astronomical research can contribute to many current questions in astronomy, cosmology, and physics.  This Springer essential is a translation of the original German 1st edition essentials, Radioastronomie by Thomas Lauterbach, published by Springer Fachmedien Wiesbaden GmbH, part of Springer Nature in 2020. The translation was done with the help of artificial intelligence (machine translation by the service DeepL.com). A subsequent human revision was done primarily in terms of content, so that the book will read stylistically differently from a conventional translation. Springer Nature works continuously to further the development of tools for the production of books and on the related technologies to support the authors.