A Bessel filter is a type of electronic filter designed to provide a smooth frequency response with minimal phase distortion. It is particularly valued in applications where signal integrity is crucial, such as in audio processing and communication systems. The filter's design allows for a gradual roll-off, which helps preserve the waveform shape of signals passing through it. One of the key characteristics of a Bessel filter is its maximally flat group delay, meaning it maintains consistent timing across different frequencies. This feature makes it ideal for applications requiring precise timing, such as in data transmission and video processing.