There is a company called Round Red Food. They make brain-phones and brain-watches and brain-televisions. These brain-things run brain-books written by Round Red Food. But Round Red Food also allows other people to write brain-books.
Round Red Food wants to control what brain-books run on their brain-things. To do this, they give each brain-book it's own long name. This is called the Brain-Thing-Name.
Brain-books are written by many people, who come and go all the time, but the brain-book is owned by a thing Round Red Food calls the Team. Round Red Food knows all the teams and gives each one it's own funny name. This is called the Team-Name.
Every brain-book needs a name, too. This name is added to the Team-Name to make the Book-Name.
Round Red Food wants to control what brain-books do so that bad Teams cannot make their brain-books do bad things like listen to you without your okay. Each brain-book has to do things. Every brain-book needs to run, but some brain-books also need to know where they are. Some need to take pictures. All sorts of stuff, but you should always be able to say okay or "No, I don't want to allow you to do that." The things that a brain-book needs to do are called its Needs-Doing-Things.
The people who write brain-books for a Team are coming and going all the time. So Round Red Food wants to know who is working for what Teams. Instead of saying "Keep your Team-Name and your Book-Names all to yourself and change them every time someone comes or goes," Round Red Food lets the people who work for a team hold onto a special thing. This special thing is a Something-Everyone-Knows/Something-Only-You-Know numbers thing. As long as both the Team and the person working for the team agree, this thing makes a promise that the person works for the team. This Promise-Paper can be broken by either the Team (if they make the person go) or the person (if they don't want to work with the Team anymore).
So, remember:
* the brain-thing has a Brain-Thing-Name;
* the brain-book has a Book-Name and a Needs-Doing-Things thing;
* the person working for the Team has a Promise-Paper
The people writing the brain-book send all this stuff to Round Red Food's Brain-Book Writer's Place. Round Red Food sends them back something that says "OK, this person, who works for Team, can put the brain-book named Book-Name on Brain-Thing-Name, and the person reading the brain-book will be asked whether they want to allow the brain-book to do its Needs-Doing-Things things."
This is called the Tearing-Hair-Out-Thing.
Brain-Thing-Name -> UDID
Book-Name -> AppID
Needs-Doing-Things -> Entitlements
Promise-Paper -> Certificate
Tearing-Hair-Out-Thing -> Provisioning Profile