What is Oracle

Oracle is one of the world's most popular relational database management system. Oracle Database is the first database designed for enterprise grid computing, the most flexible and cost effective way to manage information and applications.

The purpose of a database is to store and retrieve related information. A database server is the key to solving the problems of information management. It is produced and marketed by Oracle Corporation.

Oracle Database Editions

Below are the four editions of the Oracle database.

Enterprise Edition: It offers industry-leading scalability and reliability in both clustered and single system configurations and imposes no limitation on server resources available to the database.
Standard Edition: This is for small to medium-sized implementations. It includes Real Application Clusters and may be deployed on servers or clusters with a maximum of 2 sockets total and capped to use a maximum of 16 concurrent user threads.
Express Edition (XE): It is a free-to-use entry-level version of Oracle Database available for Windows and Linux platforms limited to using only one CPU, up to 1 GB of RAM and storing up to 11 GB of user data.
Oracle Lite: It is designed for mobile devices.