Wireless communication, or sometimes simply wireless transmission, is the transmission of information or energy between two or more points that are not connected by a conductor. Common wireless technologies use radio waves. With radio waves, the distance can be very short, such as the range of Bluetooth, which is only a few meters, or it can be millions of kilometers for deep space radio communication. It encompasses a variety of fixed, mobile, and portable applications, including two-way radios, mobile phones, personal digital assistants (PDAs), and wireless networks. Other examples of wireless technology applications include global positioning system units, garage door openers, wireless computer mice, keyboards, and headphones, headphones, radio receivers, satellite television, broadcasting, and cordless telephones. Some less common methods of achieving wireless communication include the use of other electromagnetic wireless technologies, such as light, magnetic fields, or electric fields, or the use of sound.

The term wireless has been used twice in the history of communication, with slightly different meanings. It was first used around 1890 for wireless transmission and reception technology, such as wireless telegraphy, until it was replaced by the new word radio around 1920. This term re-emerged in the 1980s and 1990s, mainly to distinguish between digital devices that communicate without wires, such as the examples listed in the previous paragraph, and those that require wires or cables. In the 2000s, the term's primary use became its application in mobile broadband, Wi-Fi, and Bluetooth technologies.

Wireless operation allows for services such as remote communication, which are impossible or impractical to use wires for. This term is commonly used in the telecommunications industry to refer to telecommunications systems (e.g. radio transmitters and receivers, remote controls, etc.). It uses some form of energy (e.g. radio waves, sound waves) to transmit information without the use of wires. Information is transmitted in this way over short and long distances.