WIFI is a technology that allows terminals such as personal computers and handheld devices (e.g., PDAs, cell phones) to connect to each other wirelessly. It is a technology that connects to the Internet through radio waves. Commonly, a wireless router, then in the wireless router's airwave coverage of the effective range can be used to WIFI connection for networking, if the wireless router is connected to an ADSL line or other Internet access line, it is also known as "hotspot".
Bluetooth (?Bluetooth?): A wireless technology standard that enables short-range data exchange (using UHF radio waves in the ISM band at 2.4-2.485GHz) between fixed devices, mobile devices, and building personal area networks.
There are actually multiple "classes" of Bluetooth technology, i.e. different versions of the core specification. The most common are Bluetooth BR/EDR (i.e., Basic Rate/Enhanced Data Rate) and Bluetooth Low Energy (Bluetooth Low Energy) technologies. Bluetooth BR/EDR is mainly used in Bluetooth version 2.0/2.1, which is generally used in products such as loudspeakers and headsets, while Low Energy Bluetooth technology is mainly used in Bluetooth version 4.0/4.1/4.2, which is mainly used in the latest products on the market, such as bracelets. The low-power Bluetooth technology is mainly used in Bluetooth version 4.0/4.1/4.2, which is mainly used in the latest products on the market, such as bracelets, smart home devices, automotive electronics, medical devices, and Beacon sensors (small transmitters that send data via Bluetooth technology).