SQLite documentation covers this quite well, see "Database File Format" [0] or have a look at pager.c source code [1]. SQLite database is actually recommended by Library of Congress for archiving [2]

0: https://www.sqlite.org/fileformat.html

1: https://sqlite.org/src/artifact/422fd8cfa59fb917

2: https://www.loc.gov/preservation/resources/rfs/data.html