RDBMS

A DBMS based on relational model is called relational database management system or RDBMS.
RDBMS uses relational structures to store data. A relation is also called a table.A relation contain tuples (rows) and attributes (columns).

STUDENT

Roll_noNameCity
10001AnuragBurhanpur
10002YashKhandwa
10003PrafulNepa nagar
10004HarshalKhanknar

MARKS

Roll_noMarks
1000192
1000281
1000378
1000485

In RDBMS tables are related each other.

Relation are set using a common column between tables.

In above tables, Roll_no is a common attribute between them which established a relation.

Check out this video lecture, for more info on RDBMS.