WordPress
In short
WordPress is a free, open-source publishing system. You use it to build and edit websites, and can extend it with add-ons.
WordPress is a CMS. The software itself is free and licensed under the GPL, which gives you the freedom to use, change and redistribute it, as wordpress.org explains. What you pay for is everything around it: hosting, themes, add-ons and someone who keeps it all up to date.
Free to use, not free to own
The strength of WordPress is that almost anything can be added with a plugin. That is also its weakness. Each plugin is code from a new supplier, and it has to be updated when security fixes come out. A site with 30 plugins has 30 things someone has to keep an eye on. We have written about what a WordPress site actually costs over time.
WordPress suits you well when you want to publish often yourself and have a fixed agreement on who runs the site. Without such an agreement, the updates tend to be left undone.
Find out whether your site runs WordPress
Open your website in a browser on a computer, right-click and choose "View page source". Search for "wp-content" with Ctrl+F. If you find it, the site runs WordPress. Then ask whoever runs the site when WordPress and the plugins were last updated, and who is responsible for it.
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