The cqlsh tool, which is also known as CQL shell, installs with Cassandra and should be used to control security, keyspace, and table definitions. Not to be confused with the old Cassandra-CLI (the deprecated Cassandra command-line interface), cqlsh will be your primary interface into controlling your Cassandra data model and analyzing cluster metadata.
If you do not have Apache Cassandra or cqlsh installed locally, you can use pip (Python's package manager) to accomplish this quickly: pip install cqlsh.
