Multi systems are those systems that allow you to work with the contents (content) in different languages.
Multilingual CMS called such CMS, which allow you to create, edit, delete content in different languages.
Pseudo multilanguage CMS called such CMS, which allow you to change interface language, but does not allow you to add or view content in different languages. FDE CMS - the first multilanguage CMS, working with content and at the interface level and at the level of content