Bluetooth is a short-range wireless technology standard used to exchange data between fixed and mobile devices over short distances using UHF radio waves in the ISM bands, 2.402 GHz to 2.48 GHz, and for the construction of personal area networks (PAN).  Originally conceived as a wireless alternative to RS-232 data cables. It is mainly used as an alternative to wired connections, to exchange files between nearby portable devices and to connect mobile phones and music players with wireless headphones. In the most widely used mode, the transmit power is limited to 2.5 milliwatts, giving you a very short range of up to 10 meters (30 feet). Due to its popularity, its use has also spread to other areas and it is very common to find Bluetooth devices in projects based on Arduino or similar. Bluetooth and Wi-Fi (Wi-Fi is the brand name for products that use the IEEE 802.11 standards) have some similar applications: network setup, printing, or file transfer. Wi-Fi is designed as a replacement for high-speed cabling for general local area network access in work areas or at home. This category of applications is sometimes called Wireless Local Area Networks (WLAN). Bluetooth was designed for notebook computers and their applications. The category of applications is described as the Wireless Personal Area Network (WPAN). Bluetooth is a replacement for wiring in various personally carried applications in any environment and also works for fixed location applications such as smart home power functionality (thermostats etc).
Wi-Fi and Bluetooth are up to a point complementary in their applications and use. Wi-Fi is usually access point centric, with an asymmetric client-server connection with all traffic routed through the access point, whereas Bluetooth is usually symmetric, between two Bluetooth devices. Bluetooth works well in simple applications where two devices need to connect with minimal settings such as a push of a button, such as in headsets and remote controls, while Wi-Fi is best suited in applications where some degree of client configuration is possible and high requirements are required. speeds. especially for network access through an access node. However, there are Bluetooth access points and ad hoc connections are possible with Wi-Fi, although not as simply as with Bluetooth. Wi-Fi Direct was recently developed to add more ad hoc Bluetooth-like functionality to Wi-Fi. In addition you will also find BLE (Bluetooth Low Energy) devices, a lower consumption wireless personal area network technology