This document introduces content management and content management systems. It discusses traditional coupled CMSs and introduces headless CMSs, which separate the content authoring from content delivery. Headless CMSs make content accessible via APIs for display on any platform. The document outlines benefits of headless CMSs like omni-channel experiences, team flexibility, front-end flexibility, and increased development speed. It categorizes headless CMSs as API-driven or git-based. Examples of headless CMS options are also provided.