what is the significance of the "com" prefix in a bundle id?

Question

I always find myself confused when using itunes connect. I understand bundleid is some kind of identifier for my app. but what is the purpose of the "com" prefix if everyone uses that? That doesn't make your bundle id any more unique?

does it matter if my bundle id is:

mycompany.app vs com.mycompany.app

I know this has been asked a lot, but I still find myself really confused by the whole process.

Answer 1

Putting the domain extension at the beginning of the name is known as Reverse Domain Name Notation. In practice it is beneficial because it provides a very specific namespace. If two companies have the same name, only one of them can own the corresponding .com domain for that name, and thus you avoid conflicts that might arise otherwise.