What is Oracle
Oracle database is a relational database management system. It is known as Oracle database, OracleDB or simply Oracle. It is produced and marketed by Oracle Corporation.

Oracle database is the first database designed for enterprise grid computing. The enterprise grid computing provides the most flexible and cost effective way to manage information and applications.

Different editions of Oracle database:-There are the four editions of the Oracle database.
  1. Enterprise Edition:- It is the most robust and secure edition. It offers all features, including superior performance and security.
  2. Standard Edition:- It provides the base functionality for users that do not require Enterprise Edition's robust package.
  3. Express Edition (XE):- It is the lightweight, free and limited Windows and Linux edition.
  4. Oracle Lite:- It is designed for mobile devices.