Here is what I figured out so far. All files seem to be saved into the same folder. The dots between names simply allow tracing the parental pages that refer to this particular page.
Say you make a page named "Users" and then make links from there to pages called "Shvarz" and "Numsgil".
You can simply call the pages "Shvarz" and "Numsgil", but when someone visits these pages, it will not be immediately clear what shvarz and numsgil are. But if you call them "Users.Shvarz" and "Users.Numsgil", then wiki will show on top that Shvarz is a subpage of "Users".
Moreover, if you don't make the page "Users", but start with making a page called "Users.Shvarz", then wiki automatically creates an empty page called "Users". This is a bit dumb, and a better way would be to prompt a user if he actually wants to create page "Users". That's why one needs to be careful about creating links to pages with long names with many dots.