Each Autodesk product is installed with a default language. A language pack is a mechanism used by some products to provide another language for the user interface and the documentation. Each language pack contains only the text strings and documents required to support a user working in the specified language; it does not duplicate the core product software.
Language packs are about 200 MB in size, so they can be installed and uninstalled quickly. A single installed product can support several languages, enabling users to switch from one to another when required.
You can uninstall language packs without uninstalling the main product. But the default language that was installed with the product cannot be separately uninstalled.