77a8603f_ervation__Library_of_Congress___Definition
[Term] Checksum [Definition] 
An algorithmically-computed numeric value for a file or a set of files used to validate the state and content of the file for the purpose of detecting accidental errors that may have been introduced during its transmission or storage. The integrity of the data can be checked at any later time by recomputing the checksum and comparing it with the stored one. If the checksums match, the data was almost certainly not altered. See also "Fixity Check."
NDSA Levels of Preservation Glossary - National Digital Stewardship Alliance - Digital Preservation (Library of Congress)
Definition