Oracle is a relational database management system it is the first database designed for enterprise grid computing.It is widely used in enterprise applications. It provides the most flexible and cost effective way to manage information and applications.
SQL Server is a Relational Database Management System developed by Microsoft. It is platform dependent and both GUI and command based software it support SQL(SEQUEL) language. It can create database, select database, drop database it is highly scalable product that can run anything from a network of cloud server. It is built for the basic function of storing and retrieving data and implemented from the specification of RDBMS.
MySQL is the world's most popular and fast open-source relational database management system. MY Sql is easy to use it handles a large subset of functionality relational database commonly used in conjunction with PHP Scripts to create dynamic server-side application and it is standard form of the well-known SQL data language.