How to explain to my client the difference between Front End and Back End?

I'm currently managing a project to bring a medium-sized shop into the online world for the first time.

The very non-technical shop owner is failing to understand what "front-end" and "back-end" means, and I was wondering if anyone had any good ideas.

He currently understands front-end to mean the part of the website that normal users will see and use, and back-end as being the admin part of the website. But of course, the admin system is still front end — he just doesn't understand this.

He also thinks that the front-end can be created by anyone, in the same way anyone can put together a newsletter using MS publisher.