mga dre!
ask ko lang po kung ano pinagkaiba ng schematics ng distortion at overdrive?
The best way to find out is to look at the schematics side by side.
Here is a schematic of the Boss SD1 Super Overdrive:
http://www.hobby-hour.com/electronics/s/schematics/boss-sd1-super-overdrive.gifand here is the Boss DS1 Distortion:
http://muztab.com/upfiles/ds1-schematic.jpgIf you disregard the switching circuits and the buffers, you'll notice that both are based on an opamp gain stage + clipping diodes + tone control. The placement of the clipping diodes influence the way the circuit distorts. In the overdrive, they are in the feedback loop of the opamp giving the circuit a softer clip. In the distortion, the diodes are at the output of the opamp gain stage, anti-parallel to ground (in some cases, Vref), clipping the signal harder.
So, in a very general sense, as Musikerochan said:
in a nut shell: overdrive has softer clipping, distortion clips harder.
However, in the past few years, the distinction between overdrive and distortion seems to be getting blurred. You have ODs with output to ground/Vref diodes in between gain stages or a combination of output to ground and feedback loop diodes. Anyway, the more variations, the merrier.