PL SQL stands for Procedural language constructs for Structured Query Language. PL SQL was introduced by Oracle to overcome the limitations of plain sql. So, pl sql adds in procedural language approach to the plain vanilla sql.
One thing to be noted over here is that pl sql is only for oracle databases. If you don’t have an Oracle database, then you cant work with PL SQL.
While, with the help of sql, we were able to DDL and DML queries, with the help of PL SQL, we will be able to create functions, triggers and other procedural constructs.