Were also moving from simple and concise to circuitous and verbose  Distortion effects generally mean both soft and hard clipping and distortion is caused by perfectly flattened peaks due to saturation or cutoff inside a transistor based unit that does not attempt to smooth the clipping of peaks will be called a distortion pedal as the transistor responds to changes in voltage quicker than a tube can while overdrive pedals usually consisting of transistor based Overdrive pedals exist in which an attempt at emulating Tubelike Distortion is made through extensive electronics and IC design will retain their typical sine wave form but will be compressed such that there is less difference between the RMS and the peak of a wave Overdrive units created with transistors much like tube amps produce clean sounds at quieter volumes and distorted warm sounds at louder volumes compared to the harsh or gritty sound of simple transistor distortion  Its going to take me a while to make sense of this