A parametric equalizer is one of the most common types of filter used in audio processing. They are fully configurable for all three parameters:
Frequency: The filter boost/ cut frequency where the filtering should happen
Q: A measure of the filter sharpness, i.e. how wide do you want the filter to boost/ cut the signal. A low Q (e.g. 0.5) means a wide effect of the filter looking like a hill. A high Q (e.g. 20) means a sharp effect looking like a sharp peak/dip.
Boost/ Cut: Controls whether you want to remove or add signal at a specific frequency
To learn more, please see the related pplication note for more info.