I have seen that several people have a profile in different languages. How does this work?

Every member can make several version of their profile in over 25 languages. To do so, go to Edit My Profile.
Then, for example, if you want to make a version of your profile in English, click on the UK flag at the bottom of your profile, and start to fill out the page in English.
When you have finished, click submit. :

Now, to make a version in another language, click on the corresponding flag on the bottom of the page and fill your profile in this language.

Please note: The language of the first profile that you fill out is, by default, already entered into other language versions of you profile. Please make sure your edits correspond to the correct language.