Difference between http://www.wordpress.org / http://www.wordpress.com
http://www.wordpress.org is totally free for bloggers, we can create our own customized website for our nature of business.
We can easily build a blog or website on WordPress.com. Hundreds of free, customization, mobile-ready designs and themes.
The main difference in both websites- .com don’t provide you code development flexibility but using the .org you can download the open-source code, write code, update code and publish your on website on your web server with specific domain name which you wants to associate, but .com doesn’t provide this kind of flexibility to developer or authors.