image

http://en.wikipedia.org/wiki/ISO_image

Disk image file formats
Optical discs	CCD/IMG/SUB   CUE/BIN   CSO   DAA   IBP/IBQ   ISO   ISZ   MDS/MDF   MDX   NRG   UIF
Hard disks	DMG   IMG   ISO   NDIF   QCOW   UDIF   VDI   VHD   VMDK   WIM
Floppy disks	ADF/ADZ   DC42/DART   DCF   DMS   IMG/IMA/IMZ   VFD
Flash drives	ISO
CD-DA	Disc Description Protocol

http://en.wikipedia.org/wiki/Disk_image TO BE READ!!!

talk about virtualization.