The followingoutline is provided as an overview of and topical guide to radio:

Radio – transmission of signals by modulation ofelectromagnetic waves withfrequencies below those ofvisible light.^[1] Electromagnetic radiationtravels by means of oscillatingelectromagnetic fields that pass through the air and thevacuum of space. Information is carried by systematically changing (modulating) some property of the radiated waves, such asamplitude,frequency,phase, or pulse width. When radio waves pass an electrical conductor, the oscillating fields induce an alternating current in the conductor. This can bedetected and transformed into sound or other signals that carry information.

Radio

• Broadcasting
• Wireless
• Radio broadcasting

• Amateur radio
• Direction finding
• Radio broadcasting
  • AM broadcasting
  • FM broadcasting
  • Shortwave broadcasting
• Radar
• Radio astronomy
• Radio navigation
• Radiotelephone
• Software-defined radio
• Two-way radio (Aviation, Land-based commercial, Government, Marine)
  • Mission critical communicationTETRA andP25
• Wireless power transfer

• Campus radio
• Commercial radio
• Community radio
• International broadcasting
• Internet radio
• Music radio
• Pirate radio
• Public radio

• Disc jockey
• Radio documentary
• Radio format
• Radio personality
• Radio programming

History of radio

• Invention of radio
• Wireless telegraphy
• Spark-gap transmitter
• Alexanderson alternator
• Antique radio
• Coherer
• Continuous wave
• Crystal radio
• Vacuum tube
• Amplitude modulation
• Old-time radio
• Radioteletype
• Table of years in radio (events by year)
• Timeline of radio

Radio science

• Antenna (radio)
• Carrier current
• Electromagnetic radiation
• Radio frequency (electricity and electromagnetic waves)
• Radio spectrum (electromagnetic waves)
• Radio propagation
• Receiver (radio)
• Transmitter
• Types of radio emissions

• Antenna matching unit
• Batteryless radio
• Digital radio
• Preselector
• Radio frequency power amplifier
• Radio software
• Superheterodyne receiver
• Tuner (radio)

• Radio stations in Africa
• Radio stations in Asia
• Radio stations in Australia
• Radio stations in Europe
• Radio stations in North America
• Radio stations in South America
• Radio stations in the South Pacific and Oceania

• Michael Faraday (predictions)
• James Clerk Maxwell (theoretical work)
• Heinrich Rudolf Hertz (experimental demonstrations)
• Oliver Lodge (techniques for transmitting and receiving radio waves)
• Guglielmo Marconi (adapted radio waves for use in signalling)
• Reginald Fessenden (developedamplitude modulation (AM) radio and first voice transmission)
• Edwin Howard Armstrong (developedfrequency modulation (FM) )

• Cable FM
• Free-space optical communication (FSO)
• Internet radio

• Bandstacked
• List of radios – List of specific models of radios
• Years in radio

• Category:Radio by country