Use low freq values for lowpass.

Use high freq values for highpass.

Lowshelf is like highpass with less attenuation.

Highshelf is like lowpass with less attenuation.

BandPass allows a band to pass and attenuates others.

Peaking boost frequencies in the band.

Notch is the inverse of BandPass.

Allpass does nothing to whitenoise.

Read more here: https://developer.mozilla.org/en-US/docs/Web/API/BiquadFilterNode