From Rosetta Code

PostgreSQL is the name of the RDBMS itself, not the language. PostgreSQL, as other RDBMSs use SQL, period. The only languages this RDBMS uses that has a different, 'exclusive' name are the procedural ones, such as PL/PgSQL, PL/Perl, PL/Python, and so on... Refer to 'Procedural Languages' section on PostgreSQL documentation [1] for more information.