What is this HeadLess CMS? What is it used for and how to retrieve data from it?

The article 'TL;DR: Headless CMS' by Andrew Brown discusses the concept of a headless CMS, which separates the content management from the presentation layer. In traditional CMS platforms like WordPress, content is managed and displayed within the same tool. A headless CMS allows content creators to adapt more easily to changing user needs by providing an API that enables access to content from various platforms. This is especially important in today's world, where users access content through many devices and applications. The article also highlights the advantages of using a headless CMS, such as flexibility, scalability, and performance. The central message is that a headless CMS can significantly enhance the process of creating and managing content in a modern approach to digital communication.