passband

This term is a technical specification used primarily in electrical engineering, telecommunications, and signal processing. It describes the specific window of frequencies that a system is designed to transmit, contrasting with the stopband, which refers to the frequencies that are blocked or attenuated.

In professional contexts, the term is often used to describe the efficiency or selectivity of a filter. A narrow passband indicates high selectivity, meaning the device is very precise about which frequencies it allows through, whereas a wide passband allows a broader spectrum of signals.