= E. F. Codd
{c}
<E. F. Codd> introduced the <relational model> in his 1970 paper on large shared data banks. Data is represented by <database relation>[relations] rather than application-visible pointers and access paths, supporting <data independence>: changing physical organization need not change the meaning of a <database query>[query].<A Relational Model of Data for Large Shared Data Banks by E. F. Codd>[abstract and §§1.1–1.3]{ref}
The distinction is operationally important. A <database query>[query] can request <database tuple>[tuples] satisfying a <predicate> while the system chooses an index or scan. Applications specify the information they need instead of navigating one fixed storage layout. Mathematical <database relation>[relations] also expose dependencies among <database attribute>[attributes], providing a foundation for <database normalization>.
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