A USB stereo headset is designed for use on computers, and combines earphones with a microphone. It is commonly used for Internet telephony and online gaming. It has the benefit of being a relatively cheap option, but the drawback of usually being wired, restricting movement.
As the name suggests, a USB stereo headset connects to a computer or games console via the USB port. This makes such a device compatible with numerous machines, and also means the computer can power the headset, meaning there is no need for separate batteries. In most cases, the term is used solely to refer to wired devices, even though theoretically, a headset could connect wirelessly to a special USB dongle or even to a wireless router. In contrast, most wireless headsets are known as Bluetooth headsets, as this is the most common wireless networking technology used for headsets.
One common use of a USB stereo headset is in Internet telephony services. These are commonly classed under the term Voice Over Internet Protocol, but many services allow video calls via a webcam as well. Another use for a USB stereo headset is in online gaming. This involved multiple players in different locations playing the same game. Using a headset allows players to talk to each other, which can be particularly useful when playing in team games and deciding on a strategy. Using a headset in this situation means that only the player's voice is picked up and transmitted to other players. If players simply used a microphone and left the sound coming out of the external speakers, each player would be able to hear the sounds from the other player's games, which would not only be confusing, but could create a very disorienting effect thanks to audio delays.
One major difference between a USB stereo headset and a wireless headset is that the former traditionally resembles a pair of earphones, with a plastic loop between the two going over the head. The device then has a separate microphone, usually on an adjustable arm. In contrast, a wireless headset will often consist simply of a one-piece device that clips onto the ear and can pick up noise from the mouth. Some online players find this more convenient, as it means they can hear other players in one ear, and the game itself in the other ear. This means the headset itself is only in mono, though usually this doesn't matter, as it isn't necessary to hear other players in stereo.