PL/SQL stands for “Procedural Language extensions to the Structured Query Language.” SQL is the now-ubiquitous language for both querying and updating—never mind the name—of relational databases. Oracle Corporation introduced PL/SQL to overcome some limitations in SQL and to provide a more complete programming solution for those who sought to build mission-critical applications to run against the Oracle database. This chapter introduces PL/SQL, its origins, and its various versions. It offers a quick summary of PL/SQL in the latest Oracle releases, Oracle Database 11g Release 1 and Release 2. Finally, it provides a guide to additional resources for PL/SQL developers and some words of advice.