Good information posted by Richard Berg regarding the different implementation

Subversion features

TFS vs. Subversion

Path space branches by using another copy of the whole folder structure. So if you branch from the very top level (which is recommended), you will see it like you have another copy of the whole source control folder structure. In the folder trees, it will only create metadata if nothing is changed. TFS implements it this way.

Version space branches by crating version tree on each of its item (file or folder).