77a8603f_ervation__Library_of_Congress___Definition
[Term] File format [Definition] 
Packages of information that can be stored as data files consisting of a fixed byte-serialized encoding of a specified information model, and/or a fixed encoding of that encoding in a tangible form on a physical storage structure.
NDSA Levels of Preservation Glossary - National Digital Stewardship Alliance - Digital Preservation (Library of Congress)
Definition