The contents of your home directory are placed on an AFS name space and is backed up regularly. AFS (Andrew File System) is a distributed networked file system, which was developed for security and scalability. Read more about AFS here.
Most differences between AFS and traditional networked file systems (like NFS) are transparant for the user, but some important differences are:
Note that since ticket-forwarding to batch jobs does not work, the only AFS-access possible from batch jobs are to read files from your Public-directory which is world-wide readable (yes, the entire world) and from the parallel file system. Use the parallel file system for data management in conjunction with batch jobs.
See File systems and Storage for some more information about AFS and the parallel file system.