**Bandwidth** is the width, usually measured in Hertz, of a frequency band. It can also be used to describe a signal, in which case the meaning is the width of the smallest frequency band within which the signal can fit. Bandwidth is related to the amount of information that can flow through a channel through the Nyquist-Shannon sampling theorem.

The **bandwidth** of an electronic filter is the part of the filter's frequency response that lies within 3 dB of its peak.

The term ** bandwidth** is also used, informally, and by extension from the above, to mean the amount of data that can be transferred through a connection in a given time period. Bandwidth is normally based on the frequencies used and the spectral spread of the information caried on the frequency.

## See also

- Shannon's law.
- Modulation.
- Signalling schemes.
- Baud rate.
- Narrowband
- Broadband.
- Latency.
- List of device bandwidths
- Latency vs Bandwidth