The main difference between a database management system, or DBMS, and a relational database management system, RDBMS, is that DBMS applications store data as files, while RDBMS applications store data in tables. DBMS is prone to data redundancy. In a RDBMS, each table has a unique identifier know as a "primary key"; this reduces the instances of data redundancy.
Data can be stored in a DBMS in either a navigational or hierarchical form. Each single data unit typically has a parent node and one or more child nodes. Accessing data is slower for large and complex amounts of data. Both data and the relationship between the data values in a RDBMS is stored in tabular form. This makes it easier and quicker to access data stored in a relational database. The data stored in the system is also logically and physically independent.
Relational databases support data integrity, advanced query capabilities, security on databases and structural independence while DBMS does not. The relational database management system is an enhanced version of the DBMS.
Most database applications are both RDBMS and DBMS compliant. This means they can maintain databases in both a tabular, or relational, form and file form. The RDBMS model is more ideal for storing large amounts of data.