You can read this screen because your eyes detect light. Light consists of electromagnetic waves. The different colors of light are electromagnetic waves of different lengths.

Visible light, however, covers only a small part of the range of wavelengths in which electromagnetic waves can be produced. Radio waves are electromagnetic waves of much greater wavelength than those of light.

The first radio astronomy observations were made in 1932 by the Bell Labs.
A few years later, the young radio engineer and amateur radio operator, Grote Reber built the first radio telescope at his home in Wheaton, Illinois, and found that the radio radiation came from all along the plane of the Milky Way and from the Sun.