Thevenin's theorem Definition and 52 Threads

what are the merits and demerits of thevenin's theorem?

Hi We've been taught how to solve circuits (of a resistive nature only, so far) using node voltage/mesh current methods and also by Thevenizing them...but I have not found (so far on the net) a proof of Thevenin's Theorem. Can anyone suggest a resource which mentions it? Cheers Vivek