WordPress is a free and open-source content management system that allows users to easily create and manage websites and blogs. It was first released in 2003 and has grown tremendously in popularity, powering over 25% of websites on the internet. While WordPress itself is free to download and use, additional expenses may include domain registration, web hosting, plugins, and themes. WordPress can be installed on a local server or hosted online and comes with many features like themes, plugins, and editors to customize websites. Its large community also provides extensive support and resources to help users build and manage their WordPress sites.