Cassandra Vs RDBMS

The following table specifying the main differences between Cassandra and RDBMS:

Cassandra	RDBMS
Cassandra is used to deal with unstructured data.	RDBMS is used to deal with structured data.
Cassandra has flexible schema.	RDBMS has fixed schema.
In Cassandra, a table is a list of "nested key-value pairs". (Row x Column Key x Column value)	In RDBMS, a table is an array of arrays. (Row x Column)
In Cassandra, keyspace is the outermost container which contains data corresponding to an application.	In RDBMS, database is the outermost container which contains data corresponding to an application.
In Cassandra, tables or column families are the entity of a keyspace.	In RDBMS, tables are the entities of a database.
In Cassandra, row is a unit of replication.	In RDBMS, row is an individual record.
In Cassandra, column is a unit of storage.	In RDBMS, column represents the attributes of a relation.
In Cassandra, relationships are represented using collections.	In RDBMS, there are concept of foreign keys, joins etc.