An equalizer is a tool used in audio processing to adjust the balance between frequency components of sound. It allows users to boost or cut specific frequency ranges, such as bass or treble, to enhance the overall sound quality. Equalizers are commonly found in music production software, home audio systems, and live sound equipment. There are different types of equalizers, including graphic and parametric equalizers. A graphic equalizer displays frequency bands on a grid, making it easy to see adjustments, while a parametric equalizer offers more control over the frequency, bandwidth, and gain. Both types help tailor audio to suit personal preferences or specific environments.