Cassandra data model was clearly explained with detailed pictorial representations as below.
Column is a Key-value pair which also contains a time-stamp along with it.
A Column that contains one or more columns (Array of columns) can be called as Super Column.
A Column Family that contains columns of related data. Column Families are accessed by row keys.
Super Column Family
A row which consists a container for array of super columns accessed by their names. Like Column Families, Super Column Families are accessed by row keys.
KeySpace in NoSQL database is just like a schema in regular RDBMS concept, Anyhow it does not have any concrete structure. In NoSQL database , there will be one keyspace per application.
A Keyspace contains column families or super columns. Each super column contains one or more column family, each column family contains at least one column.