A database system is a high-level definition of the structure and relationship between stored data, a database or databases, users and the hardware or operating system used for the storage.
A database system aims to achieve a highly organized collection of data along with appropriate tools and applications that facilitate processing and access to that data.
Most people confuse a database system with a database management system, but the two are different. A DBMS is a suite of software tools used to store and manipulate data. Database management systems come in different types, such as document store, file store and relational database management systems.
The most advanced and highly popular type of DBMS is the relational database management system. Oracle, Microsoft SQL Server, MySQL, and PostgreSQL are all examples of popular RDBMSs.