In digital forensics, analyst do disk imaging to collect information before analysis. Then why they don't use 'copy'? What is difference between disk imaging and copy?
So this is more of a language question than a programming question. A disk image is a computer file that represents the contents of a physical volume (usually). So when analysts create a disk image they are, in fact, copying data from the disk to a file.
So to creating a disk image is probably a type of copying, but they could also copy individual files. Copying could be seen as a technique, where a disk image could be seen as a type of file that is a copy of a physical drive.