Filter
An electrical network designed to perform frequency selection.
Attenuation
A reduction in frequency amplitude.
Gain
The ability of a filter to alter the amplitude of the frequency response.
Cut off Frequency
The frequency at which the attenuation of a filter reduces the output amplitude to 70.7% of its value in the pass band.
Magnification factor
The ratio of the centre frequency to bandwidth.
Notch frequency
The frequency of the band stop filter where the maximum attenuation is obtained.