What is the website wordpress.org exactly? What does it do?
Wordpress is a little similar to Tumblr. You can create blogs and publish them online. If you are a writer, then you can put your work on Wordpress and publish them online also.
It means organization :)
That's the software. wordpress.com is the service provided by running the software. If you install your own software, go to wordpress.org. If you want to have a blog, you can get one at wordpress.com.Many web hosts provide wordpress to their customers. I guess they go to wordpress.org.