On the web if searching for ‘WordPress’ you will find there are two domains that use ‘WordPress’ in them: wordpress.org and wordpress.com. And these two domains, as well as the word WordPress itself, are often used interchangeably, which is not necessarily correct.
- WordPress is the application itself. It is a free open-source web publishing application you download and install on a host server and is used to build websites and publish content on the web.
- WordPress.org is the website that hosts the WordPress open-source project. From here you can download WordPress (the application). You will also find the official documentation for WordPress, called the WordPress codex, on this site as well as the official support forum for WordPress.
- WordPress.com is a site that distributes WordPress as a software/service application. It provides a place to build a WordPress site without purchasing hosting from a host provider.
To sum things up: WordPress is the application, wordpress.org is where you download the application, and wordpress.com is a service built on top of WordPress.