residual data
(also ambient data), n.Information that has been deleted from a computer system but which persists and can be recovered using extraordinary means.
Notes
Residual information may be found in unallocated storage or in file slack space. This information is not normally accessible through the operating system, but generally requires special software to be recovered. This data came from files that have been deleted but not erased; although the pointer to the file in the file system directory has been deleted, the data remains until overwritten. Residual data may also be found in a file that contains information that has been functionally deleted, but which is not normally visible within the application.
