ATions> 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?] [Jargon File] (2001-04-24)