What does White space mean when you mount ISO

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http://unix.stackexchange.com – I mounted redhat dvd media and I named in redhat.iso. And when i mounted it and did ls it showed /media/RHEL-5.6 i386 DVD. What does this space mean between 5.6 and i386 and DVD. Because Im creating a DVD based Repository which i will use to Upgrade the Redhat linux. Im asking this because I have to assign this path in Baserul=file:///Absolute/Path to run yum upgrade command which will upgrade redhat 5.5 to 5.6. And when assign it like this baseurl=file:////media/RHEL-5.6 i386 DVD it give me error that i can only use https, ftp or URL not " " (HowTos)