What word or phrase does your mother always say?
The amount of data that can be carried by a digital communication medium, often expressed in hertz.
Note: Within the radio and microwave portions of the electromagnetic spectrum limited bandwidth is available, and in the United States the use of the spectrum is regulated and allocated by the FCC. (See VHF and UHF.)
The difference between the highest and lowest frequencies of a transmission channel (the width of its allocated band of frequencies).
The term is often used erroneously to mean data rate or capacity - the amount of data that is, or can be, sent through a given communications circuit per second.
[How is data capacity related to bandwidth?]