Let’s start with facts about the each release version of PL/SQL

PL/SQL Version 1.0
It was release as the key component of Oracle Version 6.0. At the time its release it was seen as a major advance in Oracle’s relational database technology. At the same time PL/SQL Engine was incorporated in new version of SQL*Forms V3.0. For the first time on the tools side it enables developers to code their procedural logic in a natural and straightforward manner.