Headless is a Content Management System (CMS). Here you can manage such content as a blog, the translations of your website, an image gallery or anything you can think of.
The difference with a plain old CMS is that Headless works for many many websites at the same time. All you need to do is connect your own website to Headless and then you have a CMS!
The focus of Headless is to manage content on static websites (or JAMstack websites), which we believe is the future of the web. But you can use Headless for any kind of website. If you can reach our Content API, then you can use Headless.
So how does it work?
Headless is a Content as a Service provider. We handle the server, the updates, the security and all that boring maintenance stuff. All you need to do is build a website, connect it to Headless and you're done!
There are examples of how to connect to Headless in the Quick-start.