Is rdbms obsolete?

Rdbms stands for Relational database management system.It uses tables(relations) for storing the data.In mathematical terms these tables are called relations.

Unfortunately no. They will always be with us. As long as people need representatives of some kind. Politicians will be needed. Also politics will also be around forever. It seems to be some basic...

Yes

What is the application of rdbms

well, obsolete means out of date, so the best i can think of is up to date or current.