Radio is a form of communication that has been around since the late 19th century. It is used to broadcast sound, such as music, news, and other audio content, over a distance. BROADCASTING is the process of sending out radio signals, which can be received by a TUNER, a device that tunes into specific frequencies. WIRELESS technology is also used in radio, allowing for transmission without the need for wires. AOL, HAM, and AMFM are all types of radio, with HAM being an amateur radio service and AMFM being a type of commercial radio. Radio SHACK is a retail store that sells electronic equipment, including radios, and DISNEY is a company that produces radio programs.