Bluetooth is a wireless technology standard designed for exchanging data over short distances using UHF radio waves in the ISM bands, from 2.402 GHz to 2.480 GHz. Originally conceived for creating personal area networks (PANs) to connect devices such as mobile phones, computers, and peripherals without cables, Bluetooth has since evolved to support a wide variety of applications.

Bluetooth technology was first developed in the 1990s by Ericsson, a Swedish telecommunications company. Named after Harald "Bluetooth" Gormsson, a 10th-century king known for uniting Denmark and Norway, the technology was intended to unify different communication protocols into a single standard. The Bluetooth Special Interest Group (SIG) was formed in 1998, and the first version of Bluetooth was released in 1999.

Bluetooth Low Energy (BLE), also known as Bluetooth Smart, was introduced with Bluetooth 4.0 in 2010. BLE was designed to address the growing demand for energy-efficient wireless communication for battery-powered devices, such as fitness trackers, smartwatches, and IoT sensors. Unlike classic Bluetooth, which was optimized for continuous data streaming, BLE is optimized for brief, periodic data exchanges. This makes it ideal for applications where long battery life is essential, and only small amounts of data need to be transmitted intermittently.