FallBack class in BADI implementation !!!

What is BADI ? ---> In my openion BADI(Business application addition) is the way to enhance sap standard code through object oriented concept and it provides an interface for which there can be multiple or single implementations(depends on the requirement).

Fallback class : --> If any BADI doesn't have any implementation or you can say implementation class (as interface needs one class) that time the FALLBACK class is executed. If any implementation is there FALL BACK will not come into the picture.

GET BADI and CALL BADI are the syntax to call your custom BADI.