Radio is the transmission of signals, by modulation of electromagnetic waves with frequencies below those of visible light. Electromagnetic radiation travels by means of oscillating electromagnetic fields that pass through the air and the vacuum of space. Early speculation that this required a medium of transport, called luminiferous aether, were found to be false.
Information is carried by systematically changing (modulating) some property of the radiated waves, such as their amplitude or their frequency. When radio waves pass an electrical conductor, the oscillating fields induce an alternating current in the conductor. This can be detected and transformed into sound or other signals that carry information.
Radio was my hobby... I loved radio's when growing up! The lady down the street gave me an old Zenith "Trans-Oceanic" full size console in 1953 and I spent almost two years restoring it.... it was a vintage 1953 beauty and sold for a mere $120.00! . Searching for tubes was always difficult and likely impossible today! Great sound and when it finally worked, I listened to the BBC and radio Moscow for hours!
The console radio was the center piece of every house back in the era of radio, they were big and expensive running up to $700 back in th late 1930's mostly for the rich, these radios were place in hallways and living rooms. most console radios were waist high and not very wide , as the years went on the got shorter and wider.
Most consumer console radios were made by RCA, Philco, General Electric, Wards Airline, Montgomery Ward, Westinghouse, radio-bar and many more they were all affordable.
Others like Zenith, Scott, Atwater-Kent, were mainly for the rich as there prices ran into the $500-$800 range in the 1930s and 1940s ..