The WordPress 4.4 release is the beginning of the WordPress API and from there developers have been determining how to best use this new API that is being inserted into core over the coming releases after 4.4. A Headless CMS using the WordPress API was one of first applications of this new API and probably the best one.
What is a Headless CMS?
A Headless CMS is a CMS that does not have a corresponding front-end to display any data or perform any sort of functionality. This means that the entire front-end of the CMS must be built for any pubic data to show. This might sound like a hassle but it actually very useful.
When Should You Use a Headless CMS?
For traditional websites, ones that are mainly focused on creating a static informational site, a headless CMS is not the best route to take. However if you re trying to build a web application or any sort of real-time data application you will most likely lean towards the headless CMS. By using a headless CMS you are able to use a single backend while building multiple front-ends for different device and operating systems, like an iOS application and a desktop app.
Which CMS Should I Use?
I would absolutely start to consider WordPress as a headless CMS since it is now on track to having a fully functional API. This is huge news and it really opens up the world to WordPress Developers since they are now able to use their knowledge about WordPress to create things like mobile applications.