The document discusses Content Management Systems (CMS) and their importance for managing dynamic websites. It defines a CMS as a backend system that allows non-technical users to manage a website's content, workflow, and collaboration online without needing advanced coding skills. The key aspects of a CMS covered are separating content from design, managing the content lifecycle, defining common CMS roles like editors and administrators, and how a CMS works by taking content, inserting it into templates, and publishing it for users. Popular open source CMS platforms mentioned are WordPress and Drupal.