Equalisation Effects

 An EQ pedal is used in the process of adjusting the balance between frequency components of the guitar signal. The JOYO EQ pedal strengthens (boosts) or weakens (cuts) the energy of specific frequency bands or "frequency ranges" from your pedals, rather than on the mix.
 
Equalisation can also be used to boost or reduce unwanted sounds (e.g., low hum coming from a guitar amplifier), make certain parts or voices more (or less) prominent, enhance particular aspects of the guitar tone.

Put an EQ in your amp fx loop to gain some control over your amps tone.