No, Moodle does not differ from one language to another. It is the same software no matter what language the site or course or user may be using. The function remains the same whichever language it may be shown in.
All the standard "strings" included with Moodle which show buttons, navigation, menus, settings, help, and so forth can be changed from one language to another at several levels using "Language packs". They can be further customised on your site, as well. Please see the documentation on Language for the details.
Any
content you add to a Moodle site will be in whatever language the content is written or made with. Moodle does not translate or otherwise change the language of content you add.
Moodle's language packs only change the wording for the standard
navigation and other included features.
If you have more questions about how the languages work in Moodle, including running a Moodle site using multiple language, then please take a look at the documentation pages and also the Languages forum for support.
This site is a support site about Moodle, which has communities in several languages. The forums on this site dedicated to certain languages are simply forums created for users to speak with one another in a particular language. The "Moodle in English" forums, including this one, are for use in English. If you want to get support, ask or answer questions, or chat with people in another language on this site, you can join one of the forums specifically for speakers of that language.