Have you every want to modify your car ? Well if you have then you already know the basics of what a extension is. Since you modify something that someone else has made (maybe you also made it too, but thats okay).
OR have you ever been in a situation where, you are working on something. And you thought “maybe I should write a new class to extend this other class, that way I add to the functionality”. You could do that, “could” being the keyword there. OR you could just use Extentions 🙂
Extensions let you add new functionality to existing classes, structs, enumerations, or protocols. All you have to do is extended them.