Sustain is how long a note will ring out for once its been picked. It is sortof to do with distortion because a distored note will ring out longer than if the guitar wasnt plugged into an amp.
Some distortion pedals add sustain, almost like a compressor. The sound signal is lowered, but as the note fades, the distortion adds gain to boost the signal, increasing the sustain length
Quote by breakdown123
Is there such a thing as a heavy riff with out chugging on the e string?