I found this dir in my ubuntu server
momo@myubuntuserver:/$ cd /
momo@myubuntuserver:/$ pwd
/
momo@myubuntuserver:/$ cd //
momo@myubuntuserver://$ pwd
//
momo@myubuntuserver://$ cd ///
momo@myubuntuserver:/$ pwd
/
why this dir exists ? How does it work ?