# Bluetooth

> Short-range wireless for connecting nearby gadgets: headphones, watches, keyboards.

- Level: Basic
- Topics: Networks
- URL: https://tidbit.legios.com.ar/bluetooth/
- In Spanish: [Bluetooth](https://tidbit.legios.com.ar/es/bluetooth/)

**Bluetooth** is a wireless standard for connecting devices that are close to each other, typically within about ten meters. It is what links your phone to wireless headphones, a smartwatch, a car's audio system, a keyboard or a mouse, with no cables and no need for Wi-Fi or an internet connection. Devices from different brands work together because they follow the same specification, managed by an industry group called the Bluetooth SIG.

Before two devices can talk, they **pair**: you confirm on both that they may connect, they exchange keys, and from then on they recognize each other and reconnect automatically. Bluetooth shares radio frequencies with many Wi-Fi networks and hops quickly between many narrow channels to dodge interference. Over the years it has become faster and more efficient, and newer versions add better audio and longer range.

A low-power variant, **Bluetooth Low Energy** (BLE), is made for devices that send small amounts of data now and then and must run for months on a tiny battery: fitness trackers, item finders, medical sensors, smart locks. Phones also use it to discover devices nearby. One practical note: range and quality depend a lot on walls, other radio noise and even your own body, which is why audio can stutter when the phone is in a back pocket.

## An analogy

A quiet conversation between two people standing close together. It needs no phone network or loudspeaker, but it only works within a few steps, and the two have to be introduced first.

## Keep in mind

- Connects nearby devices wirelessly, usually within about ten meters.
- Devices pair once and then reconnect by themselves.
- Bluetooth Low Energy lets small sensors run for months on a battery.
- Walls and bodies weaken the signal, which can cause dropouts.

## Go deeper

- [Bluetooth technology overview (Bluetooth SIG)](https://www.bluetooth.com/learn-about-bluetooth/tech-overview/)
- [Bluetooth on Wikipedia](https://en.wikipedia.org/wiki/Bluetooth)

## Related terms

- [Wi-Fi](https://tidbit.legios.com.ar/wi-fi/): Networking over radio waves: the internet without the cable, within a few rooms.
- [Internet](https://tidbit.legios.com.ar/internet/): A worldwide network of networks that lets any connected device reach any other.