What is the difference between wordpress.com and wordpress.org?

I run across a lot of apparent confusion regarding this question. Both wordpress.com and wordpress.org are websites. And both have to do with you getting and having a website or blog of your own.

Think of wordpress.com as a service. The wordpress.com service will provide for you free of charge a basic website or blog. Additional paid features also are available.

Think of wordpress.org primarily as a product. The wordpress.org product is a free website kit consisting of two parts:

1. a software package called “WordPress”
2. the kit instructions