SQL by itself won’t take you very far when working with databases. That’s why you need a language like PL/SQL, a procedural language that’s a superset of SQL. It builds on top of SQL adding procedural programming features, including basics like conditionals, loops, functions, objects, types, and more. Since it was created by Oracle, it works perfectly with their databases. 

PL/SQL (Procedural Language for SQL) is Oracle Corporation's procedural extension for SQL and the Oracle relational database. PL/SQL is available in Oracle Database (since version 6 - stored PL/SQL procedures/functions/packages/triggers since version 7), Times Ten in-memory database (since version 11.2.1), and IBM DB 2 (since version 9.7).