A Cassandra Keyspace is a logical namespace for a group of Column Families. A Keyspace is analogous to a database in a relational database system. Similar to the way a database contains a group of tables; a Keyspace contains a group of Column Families. Cassandra clusters can contain multiple Keyspaces. Its recommended but not required that you define one Keyspace per application. Therefore it’s common to have multiple applications share a Cassandra cluster while being logically isolated through their corresponding Keyspace. A Keyspace can be defined in the Cassandra configuration file: storage-conf.xml. Through the storage configuration file you can also configure the Keyspace replication Factory and Replica placement strategy.