RDBMS is a relational database management system.
Hadoop is a node based flat structure.
RDBMS is used for OLTP processing.
Hadoop is used for analytical and for big data processing.
In RDBMS, the database cluster uses the same data files stored in shared storage.
In Hadoop, the storage data can be stored independently in each processing node.
In RDBMS, preprocessing of data is required before storing it.
In Hadoop, you don’t need to preprocess data before storing it.