CMS (Content Management System) is a system that allows you to easily create and manage
(ie edit, add and delete) text materials and multimedia documents on the site.
CMS allows you to create new pages on the site, edit the product catalog, process orders, etc.
Recently, sites are becoming more and more complex and the tasks that CMS should solve are more and more - they should be able to adjust SEO parameters, configure and implement import and export to various systems, track conversions and events, and much more.
CMS is also called "engine", "platform".