Checksums are short digital fingerprints of data used to verify integrity, and ETags (entity tags) are unique identifiers – often derived from checksums or hashes – that web and storage systems use to track data versions and detect changes.

What Is a Checksum? (Data Integrity Basics)

A checksum is a small code calculated from a block of digital data to detect errors or alterations. By recomputing the checksum later and comparing it to the original value, you can verify whether the data has changed.

If the checksums match, the data is almost certainly unaltered.