A sound dock is a device which physically houses an mp3 or other audio player. While "docked," the player can receive a power charge. In most cases the sound dock will either have speakers or be connected to a stereo system, allowing the player to be used while it is docked, without the need for headphones.
There are two main types of sound dock. One type has an audio cable which connects to a home stereo system. This can give a good audio experience, similar to that from playing CDs, particularly on a system which can create surround sound. One drawback is that playing the music through large speakers designed for CDs can highlight the lower quality of mp3 and other digital audio files in a way not easily detectable when listening with earphones. However, this is mainly a problem for people with demanding audio standards and may not be troublesome to many more casual music listeners.
The other type of sound dock has speakers built in. This can be more convenient, though buyers will need to check reviews carefully if they are concerned about the audio quality of the speakers. Such docks have a wide range of speaker sizes, meaning that user may have a tradeoff between volume and portability.
Most sound docks can also charge the portable music player. This can be convenient as it save fiddling about with power leads, particularly for models which need bulky adaptors. However, the time it takes to recharge a device may be longer on a sound dock.
Although sound dock is the generic name for the product, many such devices are named after the iPod®, either directly or through a play on words. This is partly as a marketing tool, but partly to show the dock works specifically with the iPod®. This is important as the iPod® has specially designed data and power sockets and plugs, so may not be compatible with all sound docks. It is also worth checking before buying as not all sound docks can charge all models of iPod®.
There is also a specific product known as a SoundDock®. This product, the name of which is trademarked, is produced by Bose. It is designed for use in one room and has speakers built in. Most independent reviews suggest it is of high quality but with a high price.