What is the difference between a sector-by-sector copy and a file-level copy in forensics?

What is the difference between a sector-by-sector copy and a file-level copy in forensics?

• A. A sector-by-sector copy preserves all sectors, including unused ones; a file-level copy copies only files selected for extraction.
• B. A sector-by-sector copy copies only user-created files; a file-level copy copies raw disk sectors.
• C. A sector-by-sector copy compresses all data; a file-level copy expands all data.
• D. There is no functional difference between them.

Answer: (A)

Sector-by-sector copying captures a bit-for-bit image of the entire storage medium, including every sector and space that isn’t part of active files—unallocated space, slack space, and any hidden or system areas. This means you preserve the exact disk state, the filesystem structure, and remnants of data that may be in places other than the visible files, which is crucial for thorough forensic analysis and for maintaining a defensible chain of custody with verifiable hashes. File-level copying, in contrast, pulls only the data from files you select and copies their content and metadata, skipping the unused and unallocated areas. That makes the process faster and the resulting data smaller, but it can miss evidence stored in slack space or in deleted/unallocated regions, as well as any artifacts tied to the disk’s layout that aren’t part of the chosen files. So the key difference is completeness: sector-by-sector preserves everything on the disk, while file-level copies only the selected files, potentially leaving behind evidence outside those files.

Sector-by-sector copying captures a bit-for-bit image of the entire storage medium, including every sector and space that isn’t part of active files—unallocated space, slack space, and any hidden or system areas. This means you preserve the exact disk state, the filesystem structure, and remnants of data that may be in places other than the visible files, which is crucial for thorough forensic analysis and for maintaining a defensible chain of custody with verifiable hashes.

File-level copying, in contrast, pulls only the data from files you select and copies their content and metadata, skipping the unused and unallocated areas. That makes the process faster and the resulting data smaller, but it can miss evidence stored in slack space or in deleted/unallocated regions, as well as any artifacts tied to the disk’s layout that aren’t part of the chosen files.

So the key difference is completeness: sector-by-sector preserves everything on the disk, while file-level copies only the selected files, potentially leaving behind evidence outside those files.