Can anyone tell me what exactly is the Difference between formal exercise and body building, and they effect differently ??

Define "formal" exercise.

depends what you mean by body building.. you can't group all body building training regimens into the same group..

Usually the goal of "formal exercise" is to improve strength, health, aerobic capacity, flexability, etc, while the goal of bodybuilding is to maximize muscle size (while minimizing body fat?).

but there are several ways to do those things.