SQL PLSQL

Oracle is a relational database technology.

PLSQL stands for "Procedural Language extensions to SQL", and can be used in Oracle databases. PLSQL is closely integrated into the SQL language, yet it adds programming constructs that are not native to SQL.

Introduction

PL/SQL is a database-oriented programming language that extends Oracle SQL with procedural capabilities.

Need for PL/SQL

SQL statements are defined in term of constraints we wish to fix on the result of a query. Such a language is commonly referred to as declarative. This contrasts with the so called procedural languages where a program specifies a list of operations to be performed sequentially to achieve the desired result. PL/SQL adds selective (i.e. if...then...else...) and iterative constructs (i.e. loops) to SQL. PL/SQL is most useful to write triggers and stored procedures. Stored procedures are units of procedural code stored in a compiled form within the database.

PL/SQL Fundamentals

PL/SQL programs are organised in functions, procedures and packages.

Your first example in PL/SQL will be an anonymous block that is a short program that is ran once, but that is neither named nor stored persistently in the database.