From the TI 11 Help file:
'Backing up disks and partitions is performed in a different way: Acronis True Image Home stores a sector-by-sector snapshot of the disk, which includes the operating system, registry, drivers, software applications and data files, as well as system areas hidden from the user. This procedure is called "creating a disk image" and the resulting backup archive is often called a disk/partition image.
Acronis True Image Home stores only those hard disk parts that contain data (for supported file systems). Further, it does not back up swap file information (pagefile.sys under Windows NT/2000/XP) and hiberfil.sys (a file that keeps RAM contents when the computer goes into hibernation). This reduces image size and speeds up image creation and restoration. However, you might use the Create an image using the sector-by-sector approach option that lets you include all of the sectors of a hard disk in an image.
• A partition image includes all files and folders. This includes all attributes (including hidden and system files), boot record, and FAT (file allocation table); as well as files in the root directory and the zero track of the hard disk with master boot record (MBR).
• A disk image includes images of all disk partitions as well as the zero track with master boot record (MBR).'
Hope this helps