There are different approaches for handling multiple languages within one Confluence. Language Manager is ideal if you need the ability to provide content in various languages but want to maintain full flexibility in all of your spaces. You don't have to translate each and every piece of content. Create different content and apply different navigation menus for all your spaces in various languages for various countries - all while being able to offer translated versions of all or selected pages. 

The image shows what your users will see if there are additional languages available for the page or blog post they are looking at. The listed languages are clickable and lead to the specified page.

In order to connect different language versions of pages to each other, each page has to "know" its own language. Simply open one of those pages and click the "more" symbol. The menu will offer you Language Manager as one of the options. Click it to open the following window.

From the dropdown menu select the language of the current page. In this example we chose "English" as the correct language.

Setting the language will not change what users see at all, it's just an internal flag required for the Language Manager. 

After setting the language of the current page, more options will appear and you will be able to set language links to pages with the same content in other languages.

In order to link the current page to versions of the same page in other languages, you'll first search for the other page by typing its title into the left field. After typing at least two characters the autocomplete function will offer you available pages to make selection easier.

On the right side you'll set the language of the page you just selected. In this example we chose the German version.

As this is the first connection between two different language versions of the same page, there's no entry under "Existing language links" yet. As soon as you click on the "Add language link" button, the new connection between the current page and the selected page will be established.

Now you can continue adding additional language versions of the same page. They will each be linked to all of the others. So if you link an English, German, French and Spanish page, they all will show links to the other three pages respectively.