Bandwidth

[1] The range of audio frequencies that an audio component (radio) can handle.
[2] The width, or spread, of the range of frequencies used for a given purpose, e.g., the width of individual channels allotted to speech or to television transmissions.
[3] The space occupied in the frequency domain by signals of a specified nature, e.g., telephone quality speech, broadcast-quality stereophonic music, television, radar transmission, etc.
[4] The range of frequencies within which the characteristics of a device (filter, amplifier, etc.) are within specified limits, often the points at which the performance has changed by 3 dB from a mean level, or the half-power points .