Finding a lighter or heavier ball out of 12 balls, with only three weighings allowed

You have 12 balls out of which one is odd ie lighter or heavier than others. You can't identify the odd ball just by looking at it. So, how you would find out the ball, using the weighing scale and maximum weighings allowed are three only?

Solution Summary

A lighter or heavier ball out of 12 ballsis found, with only three weighings allowed. The solution is detailed and well presented.