Files are and have always been relational objects

“The original ‘files’ were threads upon which documents were strung chronologically for preservation.” Yates, p. 7

There never has been a notion of a file existing without a relationship to other information.

References

Yates, JoAnne. “From Press Book and Pigeonhole to Vertical Filing: Revolution in Storage and Access Systems for Correspondence.” The Journal of Business Communication (1973), vol. 19, no. 3, July 1982, pp. 5–26. https://doi.org/10.1177/002194368201900301.