The history of TV remotes is an interesting one. The very first remote control, known as the Lazy Bones, wasn’t even wireless. It was introduced by Zenith Radio Corporation in 1950 and relied on a long cable to connect to the television. The “Flash-Matic” from 1955 was the first truly wireless solution, which used a beam of visible light to send commands to the four photo cells positioned on the TV’s front panel. Infrared (IR) remotes became the industry standard by the 1980s and have managed to stick around for more than four decades.

Infrared remotes work by sending quick pulses of invisible light using an LED. The infrared receiver on the TV then decodes this signal and processes the command. If you point your phone’s camera at the front of a TV remote and press a button, you may actually be able to see the infrared LED flashing. Many modern televisions now ship with Bluetooth-enabled remotes that allow for a multitude of features like voice control and air gestures, but they still include an IR transmitter.

The truth is, infrared technology costs next to nothing to implement, especially after years of mass production and being a staple component of TV remotes. With years’ worth of TVs, soundbars and other entertainment equipment built around the standard, one of IR’s greatest strengths is compatibility. Abandoning a technology that has become synonymous with televisions wouldn’t make much sense, especially when Bluetooth and infrared can coexist in modern remotes.

A Bluetooth remote can only control your TV if it is paired to it. If you recall setting up your smart TV for the first time, you may also remember having to pair the remote — so how on earth did you control the TV before the remote was connected to it? The answer is through infrared. Your remote also uses infrared to turn the TV on, since Bluetooth might not always be active with your TV in standby mode.

I actually tested this on my TCL smart TV, which ships with a Bluetooth remote. The remote uses an infrared signal only for two operations: turning the TV on and turning it back off. Every other command, like navigating around the interface using the D-pad controls or changing the volume, was sent over Bluetooth. I then unpaired my remote from the Bluetooth settings on my TV, and guess what? My remote defaulted back to using infrared to send signals.

Bluetooth does have one big advantage — it doesn’t require a clear line of sight to communicate with the TV. So if you’re nice and comfortable in a blanket, you don’t have to dig your arm out every time you want to change the volume. Infrared technology is battery efficient, but this advantage doesn’t carry quite as much weight today, given how most TV remotes default to Bluetooth anyway. Ultimately, infrared may have stuck around to help with initial pairing and as a reliable fallback, but your TV’s remote is likely using Bluetooth most of the time. Bluetooth also allows you to use your Android phone as a remote control.