According to Wikipedia, WordPress.org is a free and open-source content management system based on PHP and MySQL. Features include a plugin architecture and a template system. It is most associated with blogging, but supports other types of web content including more traditional mailing lists and forums, media galleries, and online stores.
It is so much more than a blogging platform. You can create just about any kind of website.
You have full control over the files, documents, as well as the design and display of the content. You don’t have to know a single line of code to publish content.