The electromagnetic wave primarily used for telecommunication is the radio wave. Radio waves are a type of electromagnetic radiation with wavelengths ranging from several millimeters to hundreds of kilometers. They are generated by oscillations of electric and magnetic fields and can be used to carry information over long distances.
Telecommunication systems, such as radio broadcasting, television broadcasting, cell phone networks, Wi-Fi, and satellite communication, utilize radio waves for transmitting and receiving signals. These waves are well-suited for communication purposes because they can travel through the atmosphere and space without the need for a physical medium, like wires or cables.
Radio waves are a part of the broader electromagnetic spectrum, which encompasses various forms of electromagnetic radiation, including microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays. Each portion of the spectrum has different properties and applications, but radio waves are the most commonly used for long-distance communication due to their ability to propagate over large distances and penetrate obstacles.