The range of frequencies required for proper transmission of a signal. Bandwidth represents the amount of data that can be transmitted through a communications channel in a fixed amount of time. For digital devices, it is usually expressed in bits (or bytes) per second, whereas for analog devices, it is expressed in cycles per second, or in hertz (Hz). The greater the bandwidth, the greater the information-carrying capacity and the faster the speed. A continuous frequency range starting from zero is said to be baseband, while a range starting substantially above zero is considered broadband.