A low-pass filter is an electronic circuit that allows signals with a frequency lower than a certain cutoff frequency to pass through while attenuating (reducing) the strength of signals with frequencies higher than that cutoff. This makes it useful in various applications, such as audio processing, where it can help eliminate high-frequency noise from sound signals. In digital signal processing, low-pass filters can be implemented using algorithms to smooth out data by removing rapid fluctuations. They are commonly used in devices like audio mixers, telecommunications, and image processing to enhance the quality of the output by focusing on lower frequency components.