Hi Friends !!!

I hope everything is well.

Just wanted to request you to kindly advice on what the following terms -knobs (on a Guitar Amp \ effects) mean and do practically -

1st Combination -

Volume
Distortion
Filter

I understand the Volume and Distortion is for Increasing or decreasing the Distortion. But what does the Filter do practically ?

2nd Combination -

Volume
Bass
Mid
Treble
PRES

In this what will be an ideal setting for getting a Metallica / Heavy metal kind of Distortion ? Should the Mids be zero ?

And what does the PRES mean and do ?

Kindly advice regarding the above and help me.

Thanks and Lots of Regards
Kush