A parametric equalizer is an audio processing tool that allows users to adjust the frequency response of a sound signal. It provides control over specific frequency bands, enabling adjustments to the gain, bandwidth, and center frequency. This flexibility helps in enhancing or reducing certain sounds, making it useful in music production and live sound settings. By using a parametric equalizer, audio engineers can fine-tune the tonal quality of recordings or live performances. It is commonly found in digital audio workstations (DAWs) and hardware mixers, allowing for precise manipulation of audio to achieve the desired sound.