Digital filter

In electonics, a digital filter is an electronic filter (usually linear), in discrete time, that is normally implemented through digital electronic computation.

Note: Digital filters differ from continuous-time filters only in application. The parameters of digital filters are generally more stable than the parameters of commonly used analog (continuous) filters. Digital filters can be applied as optimal estimators. Commonly used forms are finite impulse response (FIR) and infinite impulse response (IIR).

Source: from Federal Standard 1037C and from MIL-STD-188

See also: Butterworth filter, Chebyshev filter