Many computer forensic examiners utilize the E01 forensic image file format to store bit for bit copies of hard drives used in their examinations. It is the default imaging option for many computer forensics tools and has become a defacto standard of sorts.
While somewhat lesser known, the raw image file format also produces a bit for bit copy of the contents of a drive. This format is often referred to as the DD format due to the tool which originally generated such images.
Read more on the Magnet Forensics blog.
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