"at the root" ??

I believe he is referring to the "root directory", or the "root folder". Most computer operating systems are organized in a hierarchy of folders (which are known as directories), with the outermost directory being the root. All other directories branch out of the root directory like a tree. The root directory is often represented by a lone slash "/". If you want to access a directory inside the root directory, you write a slash "/" followed by the name of the directory, like this: "/scripts". Here are a couple of resources on the subject: Linux Information Project, root Definition: http://www.linfo.org/root.html Wikipedia, Root Directory: https://en.wikipedia.org/wiki/Root_directory