A band-pass filter is an electronic device that allows signals within a specific frequency range to pass through while blocking signals outside that range. It is commonly used in audio processing, telecommunications, and radio broadcasting to isolate desired frequencies and reduce noise. These filters are characterized by their two cutoff frequencies: the lower cutoff frequency and the upper cutoff frequency. Signals that fall between these two frequencies are transmitted, while those below or above are attenuated. Band-pass filters can be implemented using various components, including resistors, capacitors, and inductors, or through digital signal processing techniques.