SQL was originally named “SEQUEL” during its development at IBM.
Donald Chamberlin and Raymond Boyce designed the language in the early 1970s for IBM’s System R relational database project. Its original name, Structured English Query Language, was shortened to SQL after a trademark conflict involving the name SEQUEL.
SQL became the dominant language for creating, querying, and managing relational databases. It can retrieve rows, combine tables, insert records, update data, define schemas, and control access, although exact features vary among database systems.
SQL is pronounced both “ess-cue-ell” and “sequel” in common usage. It is not the same as PL/SQL, Oracle’s procedural extension, or QUEL, an earlier relational database query language associated with the Ingres system.