A low-pass filter is a frequency domain filter, which allows the specified low-frequency part of the signal or data sequence to pass through, whereas the higher frequency components are attenuated. The objective is to separate from the data undesirable high frequency components, which may be due to external disturbances or noise. The filter may be characterized by the pass-band, the transition band, the stop-band and the gain or the pass-band magnitude. The smaller the transition region, the sharper is the separation between the frequency components passed and those attenuated.