The relational database model is the most popular database system and was developed by E.F. Codd in the 1970s based on tables, rows, and columns. A relational database consists of multiple tables that can be spread across and related to each other, with the first commercial relational database system being MULTICS in 1978. Examples of relational database management systems include Oracle, IBM DB2, Sybase, MySQL, and Microsoft Access.

1. • Most popular database system.
• Simple and sound theoretical basis.
• Developed by E F Codd in the early 1970's.
• The model is based on tables, rows and columns and the
manipulation of data stored within.
• Relational database is a collection of these tables.
• First commercial system: MULTICS in 1978.
• Has overtaken Hierarchical and Network models.
• Main feature: Single database can be spread across several tables.
• Examples include: Oracle, IBM's DB2, Sybase, MySQL & Microsoft
Access

2. Difference
DBMS RDBMS
1. In RDBMS relationship between two table
or file can be specified at the time of table
creation.
2. RDBMS supports client-server
architecture.
3. RDBMS supports distributed.
4. Multiple level of security
a) Log in at O.S. level
b) Command level
c) Object level
1. In DBMS relationship between two table
or file are maintained programmatically.
2. DBMS does not support client-server
architecture.
3. DBMS does not support distributed.
4. No security.