I Google searched "how does a software program locate duplicate files on a computer". These are the results plus a nice little YouTube video
https://www.youtube.com/watch?v=KEgAwXGVds4.
Duplicate file finders work by comparing files based on their content (using checksums or hash functions) and/or metadata (like file name, size, modification date). By analyzing these attributes, the software can identify files that are identical or very similar, even if they have different names.
Here's a more detailed breakdown:
1. Hashing/Checksums:
The most reliable method for identifying duplicates involves calculating a unique "fingerprint" for each file's content, often using hash functions like MD5 or SHA256.
If two files have the same hash value, it strongly suggests they are identical.
This method is effective even if the files have different names or slightly different metadata.
2. Metadata Comparison:
Some duplicate finders compare file names, sizes, and modification dates to identify potential duplicates.
This method is faster but less reliable, as files with the same name and size might still have different content.
For example, two files named "report.docx" could have different content even with the same size and date.
3. Scanning and Filtering:
Duplicate file finders scan the specified folders or drives, analyzing each file.
They then use the chosen method (hashing or metadata comparison) to identify duplicates.
Many tools offer filtering options, allowing users to narrow down the search by file type, size, or other criteria.
4. User Interface and Management:
Once the scan is complete, the software presents a list of duplicate files.
Users can review the list and choose which duplicates to remove, move, or rename.
Some tools offer automatic selection features, allowing users to quickly remove duplicates based on predefined criteria.
In essence, duplicate file finders act as specialized search tools that go beyond basic file name or size comparisons to identify true duplicates based on their content or other defining
characteristics.