Bluetooth is a wireless technology that enables you to transfer and receive data between two devices at relatively short range--similar to the way two-way radios work. You can use Bluetooth to transfer files between a phone and an accessory such as a headset, or between a phone and a PC--for example, to transfer photos between your phone and your laptop for editing and viewing.
You're likely to see two flavors of Bluetooth in the marketplace today: Bluetooth 2.1 and Bluetooth 3.0. The practical differences between versions 2.1 and 3.0 involve range and data speed. Bluetooth 2.1 supports very short-range (around 33 feet maximum) radio communication between two mobile devices. Though not ideal for transferring files, it is adequate for creating a wireless link between a phone and a Bluetooth headphone or headset.
Bluetooth 3.0 works across a much wider range and can transfer large files quickly (at a rate of around 24 mbps) via an 802.11 link. Since Bluetooth 3.0 is still relatively new, not all phones and accessories can take advantage of the speed and range that 3.0 offers.
Likewise, Wi-Fi 802.11 comes in several different protocols (a/b/g/n), each with different speeds and a different range. Having Wi-Fi on your phone allows you to connect to your home wireless network and use it to surf the Web, download apps, send e-mail, and perform other tasks. Most Wi-Fi enabled phones will at least support b/g wireless broadcasts (54 mbps for g and 11 mbps for b) as these are the most common protocols and have decent range (around 125 feet).
More-recent (and higher-end) phones also support 802.11 n, the fastest of the protocols (with raw data speeds of 600 mbps), with the largest range (around 230 feet). Be aware, however, that your connection speed is only as fast as the speed supported by the Wi-Fi router that your phone connects to; both devices must support 802.11 n in order to achieve the standard's higher speed and greater range.
This story, "Smartphone specs demystified" was originally published by PCWorld.