Function in javascript : - A function is a reuseable blockof code designed to preform a preticular Task. Its a done when its called or invoked. Reuseable Block - Coded once and used(or called) multiple times without rewriting the same(again and again) Why use Function? - Reuseability: Coded Once and used multiple time - Modularity: Break program in smaller blocks - Readability: CLean and understandable Code - Maintaninablity: Easy to fix and update logic