Bluetooth and Wi-Fi are both methods that provide wireless communication, but the difference between the two mainly stems from what they are designed to do and how they are used. The main difference is that Bluetooth is primarily used to connect devices without using cables, while Wi-Fi provides high-speed access to the internet.
Bluetooth is a wireless technology standard that is used to exchange data over short distances (less than 30 feet), usually between personal mobile devices. This means that a Bluetooth-enabled device such as a smartphone is able to communicate with other Bluetooth devices, such as a wireless headset, MP3 player or printer. Bluetooth, therefore, acts much like a cord between the two devices by creating a secure, wireless personal area network in which these devices can communicate.
Bluetooth has a wide variety of applications, and has boosted the convenience and functionality of portable devices by providing a simple way for them to interact with other Bluetooth-enabled devices. Bluetooth is considered a proprietary protocol because device manufacturers must license a number of patents in order to make and market a Bluetooth device. (Read about a different Bluetooth standard that emerged in 2011 in From Bluetooth to New Tooth: A Look at Bluetooth 4.0.)
Wi-Fi has some similar applications to Bluetooth, such as setting up a network or printing and transferring files. It is also a wireless standard, but rather than being designed to communicate between devices, it serves to wirelessly connect devices to the internet or Ethernet networks such as a corporate local area network (LAN). Its range is quite a bit larger than the very short range within which Bluetooth devices communicate, as a Wi-Fi signal can be accessed up to 300 feet away. This means that a Wi-Fi-enabled device, such as a PC or smartphone, can connect to the internet wirelessly when in a Wi-Fi "hotspot," or area in which a Wi-Fi signal may be accessed. (For more on the different types of Wi-Fi out there, see 802.What? Making Sense of the 802.11 Family.)
This hotspot can be a small area such as a single room, or may cover several miles if hotspots are allowed to overlap. Wi-Fi is a trademark name used to refer to devices that employ IEEE 802.11 standards. Product manufacturers must complete Wi-Fi interoperability certification testing, as conducted by the Wi-Fi Alliance, in order to label devices as Wi-Fi devices. Wi-Fi is available in most devices, and Wi-Fi hotspots continue to proliferate across companies, university campuses, restaurants, airports and other public locations.