A wireless microphone is a mic that has no requirement for a physical cable and transmits its sound via radio frequencies. There are two basic types, firstly where the transmitter is built into the microphone itself - which usually results in a slightly larger body than that of a standard microphone to accommodate the transmitter.
The second type utilises a body pack or belt pack as it is sometimes called. This system consists of a small black box that contains the transmitter and battery pack and is separate from the actual microphone. The box can be clipped to a belt or seated in a back pocket and has a cable extruding that connects to a headset or perhaps a guitar.
The obvious advantage is the freedom of movement this instrument gives to the artist. Disadvantages are the length of the battery life and potential interference with other radio equipment.
