WordPress.com vs WordPress.org

This question might seem a little silly but I was wondering what is the differences between WP.com and WP.org?

I know the main differences like you can’t edit a them file without paying for it, you might get some ads and you get a youname.wordpress.com domain but what are the little features that make the difference.

• WordPress.com is web service.
• WordPress.org is software product.

Think bus vs car. You can ride both, but bus is owned by someone else and what you can do with it is limited.