A content management system (CMS) is software that allows for collaborative creation and organization of documents and content, especially for publishing on websites. There are different types of CMS including complete systems like Drupal and Wordpress, blogs, and wikis. Installing a CMS involves selecting an option like doing it yourself or using an installer, then completing steps to set up the database, download and extract files, configure permissions, and complete the installation process. Drupal and Wordpress are examples of free and open source CMS that differ in their level of power and complexity to use.