I remember the first time I actually saw and held an electric guitar.
My friend got one for his birthday and invited me over to try it out. As he plugged it into the amp, I was disappointed with the sound. It just lacked something.
I tried to explain it to him, and he finally understood me.
He turned on the distortion.
As probably the most commonly used pedal across various genres, the distortion pedal has many different and interesting applications.