Detecting duplicate files across drives or partitions is the process of finding identical copies of files stored on different physical drives (like external HDDs, SSDs) or logical partitions (separate sections) of a single drive. This differs from scanning just one folder because it requires software that can access multiple file systems simultaneously. Such tools compare files using methods like file size, name, and critical checksums like MD5 or SHA to identify exact content matches, regardless of location.

This capability is vital for tasks like organizing personal media libraries across several external hard drives or consolidating project files stored on separate partitions of a workstation drive. IT administrators use it to reclaim wasted storage space on network servers spanning multiple volumes, employing tools like dupeGuru, AllDup, or specialized features in backup/archival software to find redundant data across different storage locations.

The primary advantage is significant storage space recovery and simplified file management. However, scanning across drives/partitions demands higher system resources and takes longer than local scans. Ethically, respect user privacy when scanning sensitive areas. Future developments focus on faster, distributed scanning across network storage. While accessible techniques exist, achieving comprehensive and efficient cross-drive deduplication remains an active area of development balancing thoroughness with performance.