Computer examinations

“Imaging is the process whereby an exact duplicate of the hard disk of electronic equipment or digital storage media is made. The process of imaging in the context of computer forensics is very different from an “electronic copy” of a file that an average computer user can make”.
http://www.interpol.int/Public/ICPO/PressReleases/PR2008/pdfPR200817/ipPublicReportNoCoverEN.pdf