With WordPress.com your site is hosted by WordPress and you will be assigned a subdomain website (e.g. yourname.wordpress.com). The benefit for hosting your website under WordPress.com is that it costs you nothing. However, you won’t have full access to certain features (e.g. WordPress.com does not support plugins, which are one of the most important features of WordPress). In addition, WordPress.com is “ad-supported”. This means that ads may be randomly displayed on your blog. For WordPress.org, you need to find your own web hosting firm and install the program yourself. Hence, you also need to register your own domain name. However, since it’s a program, it is customizable (you can modify and edit the CSS, themes, and html codes). Simply, you have full control over modifying your blogs to better suit your needs.