A television remote uses

A television remote control primarily uses infrared (IR) waves to communicate with the TV set. Infrared is a type of electromagnetic radiation with wavelengths longer than visible light, making it invisible to the human eye but detectable by digital cameras. The remote contains an infrared Light-Emitting Diode (LED) that flashes rapidly to send binary-coded pulses to the television [1]. These signals require a direct line-of-sight because infrared light cannot penetrate solid objects like walls [1]. While some modern remotes utilize Bluetooth or radio waves, the standard and most ubiquitous technology for home theater applications remains infrared. Other options like cosmic waves (relic radiation from the Big Bang) or microwaves are used in astronomy and high-frequency communication respectively, but not for standard TV remotes [3].

Sources

1. [1] https://www.ucl.ac.uk/culture-online/case-studies/2022/sep/how-does-remote-control-work-tv
2. [2] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 20: Earths Atmosphere > Why Are Microwaves And Some Radio Waves Not Reflected By The Ionosphere? > p. 278
3. [3] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 1: The Universe, The Big Bang Theory, Galaxies & Stellar Evolution > Cosmic Microwave Background (CMD) > p. 4