Basics of Wireless Headphones

Wireless headphones are headphones without wires. That being said, wireless headphones need a source of power (usually a battery pack in the headphones) and a transmitter that transmits the sound from the source (stereo, computer). These transmitters can use radio waves, infrared, or Bluetooth signals. With wireless or cordless headphones you get the freedom to go anywhere (within a reasonable range, of course) without being restricted or pulled back by a headphone cable and still listen to the source.
Wireless headphones are the way to go if you are in the market for headphones. Whether high or low end, wireless defeats the problem of getting your headphones ripped off your head as someone walks past you and gets tangled up. There are also great if you enjoy dancing or working out to music. With wireless, you don't risk the chance of tripping over the cord or pulling the headphones off your head.
The downfall to wireless headphones is that the range can be somewhat limited though if you get a line of sight model (usually infrared) so consider one which broadcasts like a radio station so you have more freedom to wander. Also, with cordless headphone, the farther you move from the transmitter, the lower the quality of the sound. And as the batteries begin to wear out, you will notice a drop in quality and distance. Depending on how frequently you use your headphones, the cost of batteries may become a factor in their use.
Wireless headphones can be great in the car. If you're driving down the highway and you get a call on your cell phone, having a hands-free option so you can keep both hands on the steering wheel is great idea. However, local laws may prohibit the use of headphones while operating a motor vehicle so be sure you stay on the good side of the law!