Which electromagnetic wave is commonly used in communication technologies?

Radiowaves are the type of electromagnetic waves that are most commonly used in communication technologies. This is largely due to their ability to travel long distances and penetrate through various materials, which makes them ideal for carrying signals for devices such as radios, televisions, and mobile phones.

The frequency range of radiowaves is particularly suitable for broadcasting information over vast areas, making them foundational for wireless communication systems. They can also be modulated in various ways to encode information, allowing for the efficient transmission of voice, data, and video signals.

In contrast, gamma rays and X-rays, while part of the electromagnetic spectrum, are used primarily in medical imaging and treatment due to their high energy and penetration capabilities, rather than communication. Infrared waves are used in specific applications like remote controls and short-range data communication but do not have the same range or versatility as radiowaves for widespread communication networks.