Snapshot backup operation

    Depending on the type of save operation you are performing, the
    snapshot option does the following:

    Save Type     Description
    ---------     -----------
    Volume        The snapshot type of backup saves the entire volume as it
                  presently exists, but you cannot perform incremental
                  backups using a snapshot backup as the baseline save set.

    Selected      The snapshot type of backup saves the specified files as
    Files         they presently exist, but you cannot perform incremental
                  backups using a snapshot backup as the baseline save set.