A band-pass filter is an electronic device that allows signals within a specific frequency range to pass through while attenuating frequencies outside that range. It is commonly used in audio processing, telecommunications, and radio broadcasting to isolate desired signals from unwanted noise or interference. These filters are characterized by their lower and upper cutoff frequencies, defining the bandwidth of the signals they allow. For example, a band-pass filter might be used in a radio receiver to select a particular radio frequency while blocking others, ensuring clearer reception of the desired signal.